merge: frame resize handle (bottom-right corner)

Mirrors picasso's device-resize pattern. 10x10 handle at frame's
bottom-right; pointerdown→drag→PATCH width+height on release. Min
200x150. Doesn't interfere with frame-body drag or label-as-grip
selection.

.dockerignore

@@ -15,7 +15,7 @@ data
 
 # Build artefacts
 bin
-mcables
+/cablegui
 
 # Editor cruft
 .vscode

.gitignore

@@ -8,7 +8,7 @@ data/*.db-shm
 
 # Build artefacts
 bin/
-mcables
+/cablegui
 
 # Editor
 .vscode/

CLAUDE.md

@@ -1,11 +1,11 @@
-# mCables — Project Instructions
+# CableGUI — Project Instructions
 
 ## Project Overview
 
 Cable-management **framework + solver** for m's setup. m declares his
 **devices** and the **connection requirements** between them ("NAS must
-connect to Switch via RJ45"). mCables runs a solver that emits the cable
-plan + bundle recommendations. mCables is a **schematic**, not a
+connect to Switch via RJ45"). CableGUI runs a solver that emits the cable
+plan + bundle recommendations. CableGUI is a **schematic**, not a
 physical-routing tool — cables are straight lines between endpoints; the
 "maximum bundling" objective is satisfied by the endpoint-pair rule
 (when two or more cables share the same A↔B endpoint pair, group them
@@ -13,16 +13,17 @@ into one bundle). The visual editor is still there for tweaking the
 plan, but the solver is the headline.
 
 Each cable-managed environment (LOFT, OFFICE, …) is a separate
-**mCables project**, and each project is backed by exactly one Excalidraw
+**CableGUI project**, and each project is backed by exactly one Excalidraw
 drawing. The framework provides a visual web interface backed by a Go
 HTTP API and SQLite, plus an export pipeline that writes `.excalidraw`
 files via mExDraw.
 
-**Memory group_id:** `mcables`
+**Memory group_id:** `mcables` (kept historical — all prior memories live
+under this id; renaming would orphan them)
 
 **No CLI.** Frontend-first — every interaction is through the visual
 interface. The backend serves the UI and the API; there is no
-`mcables` shell binary intended for humans.
+`cablegui` shell binary intended for humans.
 
 ## Goal
 
@@ -53,7 +54,7 @@ interface. The backend serves the UI and the API; there is no
 
 | Layer | Tech | Notes |
 |---|---|---|
-| DB | SQLite | `./data/mcables.db` (project-local, gitignored). Driver: `modernc.org/sqlite` (cgo-free). |
+| DB | SQLite | `./data/cablegui.db` (project-local, gitignored). Driver: `modernc.org/sqlite` (cgo-free). |
 | Backend | Go | `net/http` HTTP API + static frontend via `embed.FS`. Standard library + minimal deps. Single binary. |
 | Frontend | Vanilla JS modules + SVG, no build step | TypeScript types via JSDoc, optional `tsc --noEmit` in CI. Preact-via-CDN-ESM is the documented fallback if vanilla state gets painful — no build step either way. |
 | Diagram I/O | mExDraw HTTP API | `PUT https://mxdrw.msbls.de/api/drawings/<name>.excalidraw` with `Authorization: Bearer $MEXDRAW_TOKEN`. (The `mcp__mexdraw__*` MCP tools are not currently configured for this project — workers use the raw HTTP API.) |
@@ -112,14 +113,14 @@ interface. The backend serves the UI and the API; there is no
 
 ## Deployment — mDock, raw docker (NOT Dokploy)
 
-mCables runs on **mDock** (`192.168.178.131` on the LAN, Tailscale `mdock`)
+CableGUI runs on **mDock** (`192.168.178.131` on the LAN, Tailscale `mdock`)
 as a **plain docker-compose service**. Dokploy is for public mlake/mRiver
 stuff; mDock uses raw `docker compose` per the conventions of the existing
 mDock services (mgreen, mgeo, msports-garmin, paperless, …).
 
-- Repo layout on mDock: `/home/m/stacks/mcables/` with `docker-compose.yml`,
-  `data/` bind-mount, secrets in `/home/m/secrets/mcables/.env`.
-- Image: `mgit.msbls.de/m/mcables:latest` (built and pushed by a Gitea
+- Repo layout on mDock: `/home/m/stacks/cablegui/` with `docker-compose.yml`,
+  `data/` bind-mount, secrets in `/home/m/secrets/cablegui/.env`.
+- Image: `mgit.msbls.de/m/cablegui:latest` (built and pushed by a Gitea
   Actions workflow on push to `main`, runs on the self-hosted runner on
   mDock with label `self-hosted:host`).
 - Port mapping: `7777:7777`, exposed on the LAN — no reverse proxy.
@@ -127,12 +128,12 @@ mDock services (mgreen, mgeo, msports-garmin, paperless, …).
 - LAN URL: `http://mdock:7777`.
 - No auth — LAN-trusted.
 
-Local dev (no Docker): `go run ./cmd/mcables` against `./data/mcables.db`.
+Local dev (no Docker): `go run ./cmd/cablegui` against `./data/cablegui.db`.
 
 ## Seed drawing — visual grammar reference, **not** a runtime importer
 
 `mxdrw.msbls.de/draw/Cable-Management.excalidraw` is **reference material
-only**. mCables does **not** auto-ingest it. m will rebuild LOFT and OFFICE
+only**. CableGUI does **not** auto-ingest it. m will rebuild LOFT and OFFICE
 from scratch inside the tool — the seed exists so the **exporter** mimics
 its visual grammar:
 
@@ -163,13 +164,13 @@ Legend colours (global, seeded once by migration 001):
 
 ## Out of scope (v0)
 
-- Multi-user. mCables is m-only.
+- Multi-user. CableGUI is m-only.
 - Auth / sharing — LAN-trusted on mDock.
 - Mobile / responsive — desktop browser only.
 - Cable inventory beyond visual structure (no length, no purchase history,
   no SKU). Strictly visual structure for v0.
 - Import from `.excalidraw` at runtime. If a one-shot migration is ever
-  needed, a separate `mcables-migrate` CLI tool is the right shape, not a
+  needed, a separate `cablegui-migrate` CLI tool is the right shape, not a
   hot API endpoint.
 
 ## Worker Preferences

Dockerfile

@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1.7
 #
-# mCables — single-stage build → distroless runtime image.
+# CableGUI — single-stage build → distroless runtime image.
 # go.mod requires go 1.25; modernc.org/sqlite is pure Go so CGO_ENABLED=0
 # and a distroless/static runtime is all we need.
 
@@ -17,20 +17,20 @@ COPY . .
 RUN CGO_ENABLED=0 GOOS=linux go build \
         -trimpath \
         -ldflags="-s -w" \
-        -o /out/mcables \
-        ./cmd/mcables
+        -o /out/cablegui \
+        ./cmd/cablegui
 
 FROM gcr.io/distroless/static-debian12:nonroot
 WORKDIR /app
-COPY --from=build /out/mcables /app/mcables
+COPY --from=build /out/cablegui /app/cablegui
 
-ENV MCABLES_ADDR=0.0.0.0:7777 \
-    MCABLES_DB=/app/data/mcables.db
+ENV CABLEGUI_ADDR=0.0.0.0:7777 \
+    CABLEGUI_DB=/app/data/cablegui.db
 
 EXPOSE 7777
 # Run as UID:GID 1000:1000 to match m on mDock — the bind-mounted
-# /home/m/stacks/mcables/data is owned by m:m, so the container can write
+# /home/m/stacks/cablegui/data is owned by m:m, so the container can write
 # to it without chowning the host dir. distroless/static-debian12 accepts
 # arbitrary numeric UIDs; the Go binary doesn't need a /etc/passwd entry.
 USER 1000:1000
-ENTRYPOINT ["/app/mcables"]
+ENTRYPOINT ["/app/cablegui"]

Makefile

@@ -1,14 +1,14 @@
 .PHONY: build run test typecheck fmt clean
 
-BIN := bin/mcables
+BIN := bin/cablegui
 PKG := ./...
 
 build:
 	@mkdir -p bin
-	go build -trimpath -ldflags="-s -w" -o $(BIN) ./cmd/mcables
+	go build -trimpath -ldflags="-s -w" -o $(BIN) ./cmd/cablegui
 
 run:
-	go run ./cmd/mcables
+	go run ./cmd/cablegui
 
 test:
 	go test -race $(PKG)

README.md

@@ -1,9 +1,9 @@
-# mCables
+# CableGUI
 
 Cable-management **framework** for m's setup — visual web editor backed by
 a single Go binary + SQLite, generating Excalidraw drawings via mExDraw.
 
-Each cable-managed environment (LOFT, OFFICE, …) is a separate mCables
+Each cable-managed environment (LOFT, OFFICE, …) is a separate CableGUI
 *project*; each project is backed by exactly one `.excalidraw` drawing on
 mxdrw.msbls.de.
 
@@ -23,7 +23,7 @@ end-to-end; the SVG canvas is intentionally empty until slice 2.
 ## Run it
 
 ```sh
-go run ./cmd/mcables
+go run ./cmd/cablegui
 # open http://localhost:7777
 ```
 
@@ -31,18 +31,18 @@ Or built:
 
 ```sh
 make build
-./bin/mcables
+./bin/cablegui
 ```
 
 The binary serves the frontend from an embedded `web/static/` and the
-JSON API under `/api/`. SQLite lives at `./data/mcables.db` by default.
+JSON API under `/api/`. SQLite lives at `./data/cablegui.db` by default.
 
 ### Environment
 
 | Var | Default | Notes |
 |---|---|---|
-| `MCABLES_ADDR` | `0.0.0.0:7777` | Listen address. |
-| `MCABLES_DB` | `./data/mcables.db` | SQLite path. Parent dir is created on boot. |
+| `CABLEGUI_ADDR` | `0.0.0.0:7777` | Listen address. |
+| `CABLEGUI_DB` | `./data/cablegui.db` | SQLite path. Parent dir is created on boot. |
 | `MEXDRAW_BASE_URL` | `https://mxdrw.msbls.de` | Base URL for mExDraw export. |
 | `MEXDRAW_USER` | (unset) | Username for the mxdrw HTTP Basic Auth on export. Required. |
 | `MEXDRAW_PASS` | (unset) | Password for the mxdrw HTTP Basic Auth on export. Required. |
@@ -78,37 +78,35 @@ DELETE /api/cable-types/:id               ← 409 in_use if any cable references
 
 ## Deploy to mDock
 
-mCables runs on **mDock** at `http://mdock:7777` as a docker-compose
-service under `/home/m/stacks/mcables/`. Pattern matches the other
+CableGUI runs on **mDock** at `http://mdock:7777` as a docker-compose
+service under `/home/m/stacks/cablegui/`. Pattern matches the other
 mDock services (mgreen-journal, mgeo, msports-garmin, …) — no Dokploy,
 no reverse proxy, LAN-trusted.
 
-### Manual deploy (first roll)
+### Manual deploy
 
-1. **Build + push the image** (from any host with docker; today the
-   image lives in mAi's Gitea namespace because mAi doesn't have write
-   access to `m/`):
+1. **Build + push the image** (image now lives under `m/` in Gitea):
 
    ```sh
-   docker build -t mgit.msbls.de/mai/mcables:latest .
-   awk '/machine mgit.msbls.de/{getline; getline; print $2}' ~/.netrc-mai \
-     | docker login mgit.msbls.de -u mAi --password-stdin
-   docker push mgit.msbls.de/mai/mcables:latest
+   docker build -t mgit.msbls.de/m/cablegui:latest .
+   awk '/machine mgit.msbls.de/{getline; getline; print $2}' ~/.netrc \
+     | docker login mgit.msbls.de -u m --password-stdin
+   docker push mgit.msbls.de/m/cablegui:latest
    ```
 
 2. **Prepare directories on mDock** (one-time):
 
    ```sh
-   ssh mdock 'mkdir -p /home/m/stacks/mcables/data /home/m/secrets/mcables \
-              && touch /home/m/secrets/mcables/.env \
-              && chmod 0600 /home/m/secrets/mcables/.env'
-   scp docker-compose.yml mdock:/home/m/stacks/mcables/docker-compose.yml
+   ssh mdock 'mkdir -p /home/m/stacks/cablegui/data /home/m/secrets/cablegui \
+              && touch /home/m/secrets/cablegui/.env \
+              && chmod 0600 /home/m/secrets/cablegui/.env'
+   scp docker-compose.yml mdock:/home/m/stacks/cablegui/docker-compose.yml
    ```
 
 3. **Pull + start**:
 
    ```sh
-   ssh mdock 'cd /home/m/stacks/mcables && docker compose pull && docker compose up -d'
+   ssh mdock 'cd /home/m/stacks/cablegui && docker compose pull && docker compose up -d'
    ```
 
 4. **Verify** from any LAN host:
@@ -119,11 +117,11 @@ no reverse proxy, LAN-trusted.
    ```
 
 To **update** to a new build: rebuild + push the image, then
-`ssh mdock 'cd /home/m/stacks/mcables && docker compose pull && docker compose up -d'`.
+`ssh mdock 'cd /home/m/stacks/cablegui && docker compose pull && docker compose up -d'`.
 
 ### Persistence
 
-SQLite lives at `/home/m/stacks/mcables/data/mcables.db` on the host
+SQLite lives at `/home/m/stacks/cablegui/data/cablegui.db` on the host
 (bind-mounted into the container at `/app/data`). Container runs as
 UID 1000:1000 to align with `m:m` ownership on mDock — DB files end
 up owned by `m`, the host user.

cmd/cablegui/main.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"log"
+	"net/http"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"syscall"
+	"time"
+
+	"mgit.msbls.de/m/cablegui/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/server"
+	"mgit.msbls.de/m/cablegui/web"
+)
+
+func main() {
+	addr := envOr("CABLEGUI_ADDR", "0.0.0.0:7777")
+	dbPath := envOr("CABLEGUI_DB", "./data/cablegui.db")
+
+	if err := os.MkdirAll(filepath.Dir(dbPath), 0o755); err != nil {
+		log.Fatalf("mkdir data dir: %v", err)
+	}
+
+	store, err := db.Open(dbPath)
+	if err != nil {
+		log.Fatalf("open db: %v", err)
+	}
+	defer store.Close()
+
+	if err := db.Migrate(store.DB()); err != nil {
+		log.Fatalf("migrate: %v", err)
+	}
+
+	srv := &http.Server{
+		Addr:              addr,
+		Handler:           server.New(store, web.Static()),
+		ReadHeaderTimeout: 5 * time.Second,
+	}
+
+	go func() {
+		log.Printf("cablegui listening on %s (db=%s)", addr, dbPath)
+		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+			log.Fatalf("listen: %v", err)
+		}
+	}()
+
+	stop := make(chan os.Signal, 1)
+	signal.Notify(stop, os.Interrupt, syscall.SIGTERM)
+	<-stop
+	log.Printf("shutting down")
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	_ = srv.Shutdown(ctx)
+}
+
+func envOr(key, fallback string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return fallback
+}

docker-compose.yml

@@ -1,20 +1,20 @@
-# mCables — production compose for mDock.
-# Lives at /home/m/stacks/mcables/docker-compose.yml on mDock.
+# CableGUI — production compose for mDock.
+# Lives at /home/m/stacks/cablegui/docker-compose.yml on mDock.
 # Matches the existing mDock service patterns (mgreen, mgeo, …).
 
 services:
-  mcables:
-    image: mgit.msbls.de/m/mcables:latest
-    container_name: mcables
+  cablegui:
+    image: mgit.msbls.de/m/cablegui:latest
+    container_name: cablegui
     restart: unless-stopped
     ports:
       - "7777:7777"
     environment:
       - TZ=Europe/Berlin
-      - MCABLES_ADDR=0.0.0.0:7777
-      - MCABLES_DB=/app/data/mcables.db
+      - CABLEGUI_ADDR=0.0.0.0:7777
+      - CABLEGUI_DB=/app/data/cablegui.db
     env_file:
       # MEXDRAW_USER + MEXDRAW_PASS for the mxdrw HTTP Basic Auth on export.
-      - /home/m/secrets/mcables/.env
+      - /home/m/secrets/cablegui/.env
     volumes:
-      - /home/m/stacks/mcables/data:/app/data
+      - /home/m/stacks/cablegui/data:/app/data

docs/design.md

@@ -1,4 +1,4 @@
-# mCables — Design v4.1
+# CableGUI — Design v4.1
 
 Cable-management **framework + solver** for m's setup. Inventor shift 1
 design, revised through v2 (rescope to multi-project framework), v3
@@ -6,7 +6,7 @@ design, revised through v2 (rescope to multi-project framework), v3
 **v4.1 — six locked answers from m's v4 review**.
 
 > **What changed in v4.1** (tight pass on v4)
-> 1. **mCables is a schematic, not a physical-routing tool.** Cables are
+> 1. **CableGUI is a schematic, not a physical-routing tool.** Cables are
 >    straight lines between endpoints; the solver and the renderer do not
 >    care about paths, trunks, frame edges, or cable-tray polylines.
 >    "Maximum bundling" reduces to the v3 rule: **≥2 cables between the
@@ -33,13 +33,13 @@ design, revised through v2 (rescope to multi-project framework), v3
 
 Sources: the live `Cable-Management.excalidraw` on mxdrw.msbls.de (used as
 the *visual-grammar reference*, not a bootstrap import target),
-`mai-memory` (`mcables`, `m`), and the live mDock services for deploy
+`mai-memory` (`cablegui`, `m`), and the live mDock services for deploy
 conventions (§10). v4 driven by m's product-vision clarification:
 
 > "we provide a cable manager — I say what devices we have, the app tells
 > me how to bundle cables and how the most efficient connection looks like"
 
-mCables shifts from a manual draw-and-click editor to a **solver** that
+CableGUI shifts from a manual draw-and-click editor to a **solver** that
 takes a list of devices + the connections m needs and emits the cable
 plan + bundle recommendations. The manual editor stays (it's the only way
 to inspect + tweak the plan) but is no longer the primary surface.
@@ -60,7 +60,7 @@ to inspect + tweak the plan) but is no longer the primary surface.
 >   without applying; default applies.
 > - **Solver objective: maximum bundling** (§5b.1). Schematic only: when
 >   two or more cables share the same endpoint pair, group them into one
->   bundle. No path or trunk geometry — mCables is a wiring schematic,
+>   bundle. No path or trunk geometry — CableGUI is a wiring schematic,
 >   not a routing tool. v4.1 strips all path/trunk language from the v4
 >   draft.
 > - **UI: device-type dropdown** on device-create, **Connection
@@ -72,7 +72,7 @@ to inspect + tweak the plan) but is no longer the primary surface.
 >   bundle-rendering polish.
 >
 > **What carried over from v3 (unchanged in v4)**
-> - mCables is a framework: top-level `projects`, each backed by one
+> - CableGUI is a framework: top-level `projects`, each backed by one
 >   `.excalidraw` drawing. `UNIQUE(projects.name)`.
 > - `cable_types` is global. Migration 001 seeds Power/USB/HDMI/DP/RJ45.
 > - `devices` UNIQUE(project_id, name); `frame_id` nullable; FrameRef
@@ -81,8 +81,8 @@ to inspect + tweak the plan) but is no longer the primary surface.
 > - `projects.drawing_name` auto-defaults to `<name>.excalidraw`.
 > - `DELETE /api/projects/:pid?confirm=<name>` guardrail.
 > - No cable inventory metadata; visual + connectivity structure only.
-> - DB at `./data/mcables.db` (gitignored). Bind `0.0.0.0:7777` LAN, no auth.
-> - Deploy on mDock under `/home/m/stacks/mcables/`, raw docker-compose.
+> - DB at `./data/cablegui.db` (gitignored). Bind `0.0.0.0:7777` LAN, no auth.
+> - Deploy on mDock under `/home/m/stacks/cablegui/`, raw docker-compose.
 >
 > **What's superseded in v4**
 > - The "manual draw-a-cable port-to-port" flow from v3 §7 is *kept* as a
@@ -97,7 +97,7 @@ to inspect + tweak the plan) but is no longer the primary surface.
 
 `Cable-Management.excalidraw` on mxdrw.msbls.de is **not** ingested at
 runtime. It is the visual-grammar reference we lock the export onto so that
-when m rebuilds LOFT and OFFICE inside mCables, the exported `.excalidraw`
+when m rebuilds LOFT and OFFICE inside CableGUI, the exported `.excalidraw`
 looks like the seed.
 
 Concrete numbers from the live file (180 elements):
@@ -128,7 +128,7 @@ Three observations about the seed's visual grammar — these constrain the
 1. **Ports sit on a device edge as small ellipses (~12×9)**, coloured by
    cable type. They are not children of the device in the Excalidraw sense
    (no `containerId`/`boundElements` link) — purely positional. When we
-   export from mCables we mimic that: port ellipse at `(device.x +
+   export from CableGUI we mimic that: port ellipse at `(device.x +
    port.x_offset, device.y + port.y_offset)`, stroke colour = type colour.
 2. **Cable arrows bind to elements**. In the seed: 44 endpoints to ellipses
    (ports), 12 to whole rectangles (device-level, no specific port), 3 to
@@ -161,7 +161,7 @@ painful: switch to Preact-via-CDN-ESM (still no build step). Not v0.
 
 ## 2. SQLite schema
 
-`./data/mcables.db` (project-local, gitignored). WAL mode, FKs on.
+`./data/cablegui.db` (project-local, gitignored). WAL mode, FKs on.
 Driver: **`modernc.org/sqlite`** (cgo-free — clean cross-compile, simple
 Dockerfile).
 
@@ -609,8 +609,8 @@ cascade does **not** touch `cable_types` (no FK to projects).
 
 ## 3. Go HTTP API
 
-Single binary `cmd/mcables`, `net/http`, no router framework. Listens on
-`0.0.0.0:7777` by default (overridable via `MCABLES_ADDR`). Static frontend
+Single binary `cmd/cablegui`, `net/http`, no router framework. Listens on
+`0.0.0.0:7777` by default (overridable via `CABLEGUI_ADDR`). Static frontend
 from `embed.FS` at `/`, JSON API under `/api/`.
 
 ```
@@ -780,7 +780,7 @@ generated scene JSON.
 
 ## 4. Export — DB → Excalidraw (visual-grammar conformance)
 
-mCables generates a `.excalidraw` scene from a project's rows. The seed
+CableGUI generates a `.excalidraw` scene from a project's rows. The seed
 drawing's grammar is the contract.
 
 ### 4.1 Element mapping
@@ -798,7 +798,7 @@ drawing's grammar is the contract.
 
 ### 4.2 Element IDs are stable across exports
 
-Every mCables row carries `excalidraw_id` (TEXT, generated on first export
+Every CableGUI row carries `excalidraw_id` (TEXT, generated on first export
 via `crypto/rand` → 21-char Excalidraw-style ID). On re-export the same row
 reuses the same ID. This means:
 
@@ -866,7 +866,7 @@ left strictly alone — the solver only adds and removes its own.
 
 ### 5b.1 Objective: maximum bundling — schematic only
 
-mCables is a **schematic**, not a physical-routing tool. Cables are
+CableGUI is a **schematic**, not a physical-routing tool. Cables are
 straight lines between endpoints; the solver has no model of walls,
 floors, cable trays, or path geometry. "Maximum bundling" therefore
 reduces to a single rule on the schematic:
@@ -988,7 +988,7 @@ triggers a debounced re-solve) is parked at slice 9+ as an opt-in.
 
 ```
                 ┌─────────────────────┐
-                │ mCables DB (truth)  │
+                │ CableGUI DB (truth)  │
                 └──────────┬──────────┘
                            │
               export       ▼
@@ -998,11 +998,11 @@ triggers a debounced re-solve) is parked at slice 9+ as an opt-in.
                        └────────────────────────┘
 ```
 
-- mCables UI → DB: synchronous (every drag/add/remove persists immediately).
+- CableGUI UI → DB: synchronous (every drag/add/remove persists immediately).
 - DB → Excalidraw: **manual** button "Export to Excalidraw" in the header,
   per project. Calls `POST /api/projects/:pid/sync/export`.
 - Excalidraw → DB: **not implemented** in v0. Anything m draws in
-  Excalidraw stays in Excalidraw until he redraws it in mCables.
+  Excalidraw stays in Excalidraw until he redraws it in CableGUI.
 
 This keeps the v0 scope tight: no conflict resolution, no element-diff
 import, no auto-debounce. mExDraw keeps its own version history (git
@@ -1012,7 +1012,7 @@ When mxdrw is unreachable: the export button shows a tooltip and disables;
 the editor keeps working against the local DB.
 
 Post-MVP, import returns as a one-shot migration tool (separate
-`mcables-migrate` CLI tool, not part of the running server) for seeding
+`cablegui-migrate` CLI tool, not part of the running server) for seeding
 new projects from existing `.excalidraw` files.
 
 ---
@@ -1023,7 +1023,7 @@ The editor lives at `/`. Layout:
 
 ```
 ┌────────────────────────────────────────────────────────────────────┐
-│ mCables   [LOFT ▾ projects-picker]            [Export] [+ Project] │  ← header
+│ CableGUI   [LOFT ▾ projects-picker]            [Export] [+ Project] │  ← header
 ├────────┬───────────────────────────────────────────────────────────┤
 │        │                                                           │
 │ Legend │                                                           │
@@ -1254,7 +1254,7 @@ Slices 9+ (not promised for the first coder shift):
 - Cable inventory metadata (length/SKU) if m later wants it.
 - Dark mode.
 
-Out of scope, period (would change mCables's mental model): path
+Out of scope, period (would change CableGUI's mental model): path
 routing, cable-tray polylines, frame-edge corridors, wall-axis bundling,
 3D, anything that treats a cable as more than a labelled endpoint pair.
 
@@ -1264,7 +1264,7 @@ routing, cable-tray polylines, frame-edge corridors, wall-axis bundling,
 
 The six v4 questions are now answered. Locked answers:
 
-1. **Where do paths come from?** → **Nowhere — mCables is a schematic.**
+1. **Where do paths come from?** → **Nowhere — CableGUI is a schematic.**
    Cables are straight lines between endpoints. The solver does not
    route, the renderer does not route, and "maximum bundling" reduces to
    the endpoint-pair rule (§5b.1). Anything resembling a path, trunk,
@@ -1307,25 +1307,25 @@ before writing this:
 - Host port mappings: deliberately collision-free across the host. Existing
   high ports in use include 3300 (mgreen), 3077 (paperless-ai), 7878
   (radarr), 8082 (mgeo-tileserver), 8989 (sonarr), 9696 (prowlarr).
-  **Port 7777 is free** — taking it for mCables.
+  **Port 7777 is free** — taking it for CableGUI.
 - Bind-mount volumes: `/home/m/<project>-data:/app/data` is the canonical
   pattern (mgreen). For project-local data we put `data/` *next to* the
   compose file so a `git pull && docker compose up -d` is the whole deploy:
-  `/home/m/stacks/mcables/data:/app/data`.
+  `/home/m/stacks/cablegui/data:/app/data`.
 - Secrets via `env_file: /home/m/secrets/<project>/.env` (msports-garmin
-  pattern). mCables only needs `MEXDRAW_TOKEN` for export.
+  pattern). CableGUI only needs `MEXDRAW_TOKEN` for export.
 - No reverse proxy on mDock. Services expose ports directly on the LAN
   (mDock = `192.168.178.131` / Tailscale `mdock`). Public exposure goes via
-  mlake/Dokploy + Caddy when needed — out of scope for mCables (LAN-only).
+  mlake/Dokploy + Caddy when needed — out of scope for CableGUI (LAN-only).
 - Auto-deploy via the Gitea Actions self-hosted runner already installed
   on mDock (`/home/m/act-runner/`, label `self-hosted:host`). Push to
   `main` → workflow on mDock → `docker compose up --build -d`.
 
-### Repo layout for mCables
+### Repo layout for CableGUI
 
 ```
-mCables/
-├── cmd/mcables/main.go        # Go binary
+CableGUI/
+├── cmd/cablegui/main.go        # Go binary
 ├── internal/
 │   ├── db/                    # migrations + store
 │   ├── importer/              # post-MVP only (not in MVP)
@@ -1336,7 +1336,7 @@ mCables/
 │   ├── main.js                # ES module entry
 │   ├── style.css
 │   └── lib/...                # SVG helpers, store, components
-├── data/                      # mCables runtime DB lives here (gitignored)
+├── data/                      # CableGUI runtime DB lives here (gitignored)
 │   └── .gitkeep
 ├── docs/design.md             # this file
 ├── Dockerfile
@@ -1361,37 +1361,37 @@ COPY go.mod go.sum ./
 RUN go mod download
 COPY . .
 RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -ldflags="-s -w" \
-        -o /out/mcables ./cmd/mcables
+        -o /out/cablegui ./cmd/cablegui
 
 FROM gcr.io/distroless/static-debian12:nonroot
 WORKDIR /app
-COPY --from=build /out/mcables /app/mcables
-ENV MCABLES_ADDR=0.0.0.0:7777
-ENV MCABLES_DB=/app/data/mcables.db
+COPY --from=build /out/cablegui /app/cablegui
+ENV CABLEGUI_ADDR=0.0.0.0:7777
+ENV CABLEGUI_DB=/app/data/cablegui.db
 USER nonroot:nonroot
 EXPOSE 7777
-ENTRYPOINT ["/app/mcables"]
+ENTRYPOINT ["/app/cablegui"]
 ```
 
-### docker-compose.yml (on mDock at `/home/m/stacks/mcables/`)
+### docker-compose.yml (on mDock at `/home/m/stacks/cablegui/`)
 
 ```yaml
 services:
-  mcables:
-    image: mgit.msbls.de/m/mcables:latest
-    container_name: mcables
+  cablegui:
+    image: mgit.msbls.de/m/cablegui:latest
+    container_name: cablegui
     restart: unless-stopped
     ports:
       - "7777:7777"
     environment:
       - TZ=Europe/Berlin
-      - MCABLES_ADDR=0.0.0.0:7777
-      - MCABLES_DB=/app/data/mcables.db
+      - CABLEGUI_ADDR=0.0.0.0:7777
+      - CABLEGUI_DB=/app/data/cablegui.db
       - MEXDRAW_BASE_URL=https://mxdrw.msbls.de
     env_file:
-      - /home/m/secrets/mcables/.env       # contains MEXDRAW_TOKEN
+      - /home/m/secrets/cablegui/.env       # contains MEXDRAW_TOKEN
     volumes:
-      - /home/m/stacks/mcables/data:/app/data
+      - /home/m/stacks/cablegui/data:/app/data
 ```
 
 LAN URL: `http://mdock:7777` (or `http://192.168.178.131:7777`).
@@ -1412,15 +1412,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Build image
-        run: docker build -t mgit.msbls.de/m/mcables:latest .
+        run: docker build -t mgit.msbls.de/m/cablegui:latest .
       - name: Push image
         run: |
           echo "${{ secrets.GITEA_TOKEN }}" | \
             docker login mgit.msbls.de -u mAi --password-stdin
-          docker push mgit.msbls.de/m/mcables:latest
+          docker push mgit.msbls.de/m/cablegui:latest
       - name: Up
         run: |
-          cd /home/m/stacks/mcables
+          cd /home/m/stacks/cablegui
           docker compose pull
           docker compose up -d
 ```
@@ -1428,7 +1428,7 @@ jobs:
 ### Local-development run (no Docker)
 
 ```
-make run          # go run ./cmd/mcables → :7777 against ./data/mcables.db
+make run          # go run ./cmd/cablegui → :7777 against ./data/cablegui.db
 make typecheck    # tsc --noEmit on web/
 make test         # go test ./...
 ```
@@ -1438,4 +1438,228 @@ gitignored.
 
 ---
 
-DESIGN v4.1 READY FOR REVIEW
+## 11. v5 — Cable routing via clamps
+
+m's bundling primitive: a **clamp** is a physical anchor on the canvas
+(think cable tie / clip). A cable routes from its `from` endpoint,
+through zero or more clamps **in order**, to its `to` endpoint. Two
+cables that share an ordered pair of consecutive clamps are visibly
+bundled along that segment — no detection pass, no inference: the
+overlap *is* the bundle.
+
+This replaces the abandoned waypoints + segment-detection approach.
+v0's straight-line schematic stays as the empty-clamps case
+(`cable_clamps` is empty for a fresh solver-emitted cable).
+
+### 11.1 Schema (migration 007)
+
+```sql
+CREATE TABLE clamps (
+    id              INTEGER PRIMARY KEY,
+    project_id      INTEGER NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
+    x               REAL NOT NULL,
+    y               REAL NOT NULL,
+    label           TEXT NOT NULL DEFAULT '',
+    frame_id        INTEGER REFERENCES frames(id) ON DELETE SET NULL,
+    excalidraw_id   TEXT,
+    created_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    UNIQUE (project_id, excalidraw_id)
+);
+CREATE INDEX clamps_project_idx ON clamps(project_id);
+
+CREATE TABLE cable_clamps (
+    cable_id        INTEGER NOT NULL REFERENCES cables(id) ON DELETE CASCADE,
+    clamp_id        INTEGER NOT NULL REFERENCES clamps(id) ON DELETE CASCADE,
+    ord             INTEGER NOT NULL,    -- 1..N along from→to
+    PRIMARY KEY (cable_id, ord),
+    UNIQUE (cable_id, clamp_id)          -- a cable can't visit the same clamp twice
+);
+CREATE INDEX cable_clamps_clamp_idx ON cable_clamps(clamp_id);
+```
+
+`frame_id` on clamps mirrors devices + IO markers — m can put a clamp
+inside a frame and the frame-drag carries it.
+
+`UNIQUE (cable_id, clamp_id)` blocks loops. `ord` is a small int, 1-based;
+nothing requires it to be contiguous (m can renumber 1, 2, 3 → 1, 3, 5
+during edits and the renderer is fine with that), but the UI keeps them
+contiguous on every mutation for sanity.
+
+### 11.2 Cable rendering model
+
+Each cable resolves to a polyline `[from-anchor, clamp₁, clamp₂, …, clampₙ, to-anchor]`
+where:
+- `from-anchor` / `to-anchor` come from the existing `anchorForEndpoint`
+  resolver (port / device / IO).
+- clamp anchors are `(clamp.x, clamp.y)` directly — clamps don't have a
+  width/height to centre.
+
+For N=0 clamps the result is the v0 straight line. For N≥1 we render
+a `<polyline>` instead of a `<line>`.
+
+The endpoint-replug handles from §10 (cable-replug) stay on the **first
+and last** vertices. Mid-polyline vertices get their own clamp-handle —
+small grab points only on the selected cable, which behave like
+clamp-detach when dragged onto empty canvas (drop a clamp off the
+cable's path).
+
+### 11.3 Bundle visualisation — derived from shared segments
+
+A **segment** is a directed pair `(A, B)` where A and B are consecutive
+nodes of a cable's polyline. Two cables share a segment when their
+polyline contains the same A→B (or B→A — segment matching is
+undirected).
+
+For each segment, compute `cables[]` — the cables that traverse it.
+If `len(cables) ≥ 2`, render the segment as a single thick line on top
+of the individual ones:
+
+- **Width**: `2 + N` px (N = cable count). Caps at ~12 px.
+- **Colour**: a striped pattern, one stripe per distinct cable type in
+  the bundle, ordered by cable_type.id. SVG `<linearGradient>` with
+  hard stops produces the stripe band cheaply; render it on a sibling
+  `<polyline>` over the individual lines.
+- **Tooltip**: `<title>` child listing the cables ("Power · USB · HDMI").
+
+At a clamp where ≥ 2 cables meet, the clamp icon (10×10 rounded square)
+shows a small count badge (`×N`) when N > 1. At fan-out points
+(endpoint with no clamp before it on the polyline) the individual
+coloured lines re-emerge, so m sees which port each strand goes to.
+
+Shared-segment computation is O(C·N̄) where C = #cables and N̄ = average
+polyline length. For a v0-sized project (≤ ~30 cables, ≤ ~5 clamps per
+cable) this is trivial. We rebuild the segment map on every renderCanvas
+— no caching layer.
+
+### 11.4 UI gestures
+
+**+ Clamp tool (`C` shortcut, also a sidebar button):**
+- Click empty canvas → place a clamp at the cursor (POST `/clamps`).
+  Standalone clamp — not on any cable yet.
+- Click a cable line → insert this clamp into that cable. The new clamp
+  sits at the click position (snapped to the nearest point on the
+  cable's polyline) and its `ord` is computed so it falls between the
+  two existing vertices it lies between.
+
+**Drag a cable's mid-segment:**
+- Pointerdown on a cable line (not on an endpoint handle) and drag.
+  Live preview shows a bend at the cursor. Pointerup:
+  - If the cursor is within snap-radius (~16 px) of an existing clamp:
+    insert that clamp into the cable's polyline at the right `ord`.
+  - Otherwise: create a fresh clamp at the release point and insert it.
+
+**Clamp inspector** (selecting a clamp on the canvas):
+- Position (x, y editable + label)
+- "Cables through this clamp": list with each cable's two endpoints,
+  click → select that cable
+- "Remove from this cable" (per row) → DELETE the matching cable_clamps
+  row; cable's polyline collapses around the gap.
+- "Delete clamp" → cascade-removes from every cable_clamps row.
+
+**Right-click on a clamp icon ON a cable** → "Remove from this cable"
+inline.
+
+**Frame drag** carries clamps the same way it carries devices + IO
+markers (clamp.frame_id mirrors the existing pattern, drag handler
+already iterates frame-contained items).
+
+### 11.5 Relationship to the existing `bundles` table
+
+**Recommendation: keep `bundles` and `bundle_cables`, repurpose them.**
+
+- Implicit/auto bundles → derived live from shared clamp segments. No
+  DB rows. The §5 `GET /bundles/suggestions` endpoint stays useful as a
+  "you might want to route these through the same clamps" hint.
+- Explicit named bundles → still in the `bundles` table. m names a
+  group ("desk → wall trunk"), the UI offers "route all members through
+  these clamps" as a one-click action. Useful for the case where m
+  wants a stable label on a logical bundle that isn't yet routed.
+
+Migration 007 leaves `bundles` + `bundle_cables` untouched. A v6 cleanup
+can drop them if m decides the explicit-named path isn't worth keeping.
+
+### 11.6 Solver coupling
+
+The v0 solver still emits **straight cables** — no clamp rows. m
+hand-routes after Solve. The solver's preview-diff is unaffected
+(solver compares endpoint pairs; clamp routing is independent of the
+endpoint identity).
+
+Future v5.1: solver-suggested clamps based on shared paths between
+endpoint pairs. Out of scope here.
+
+### 11.7 Export to mxdrw
+
+Clamps map to small diamond elements (separate from IO markers — IO
+diamonds are red wall-outlets; clamps are grey routing points).
+`excalidraw_id` is stable across re-exports per the existing pattern.
+
+Cable arrows become Excalidraw `arrow` elements with mid-points (the
+clamp positions) when N≥1 — Excalidraw supports multi-vertex arrows
+via the `points` array. Each `startBinding` / `endBinding` resolves to
+the from/to anchor's excalidraw_id; mid-vertices are unbound.
+
+Bundle visualisation (thick striped lines on shared segments) is **not
+exported** in v0 — Excalidraw doesn't natively support gradient strokes,
+and the mxdrw round-trip would lose them. We export each cable as its
+own polyline; bundling is a viewer-only concept.
+
+### 11.8 API additions
+
+```
+POST   /api/projects/:pid/clamps                   { x, y, label?, frame_id? } → Clamp
+PATCH  /api/projects/:pid/clamps/:id               { x?, y?, label?, frame_id? } → Clamp
+DELETE /api/projects/:pid/clamps/:id
+
+POST   /api/projects/:pid/cables/:cid/clamps       { clamp_id, ord? } → CableClamp
+DELETE /api/projects/:pid/cables/:cid/clamps/:cmid
+
+# Convenience: re-order clamps on a cable in one call
+PUT    /api/projects/:pid/cables/:cid/clamps       { clamp_ids: [int, int, …] }
+```
+
+Snapshot endpoint grows two arrays:
+- `clamps: []Clamp`
+- `cable_clamps: []{ cable_id, clamp_id, ord }`
+
+### 11.9 Open questions for m
+
+1. **Clamp icon shape.** Diamond (overlaps visually with IO markers
+   when zoomed out), small filled circle (overlaps with port circles),
+   or rounded square `▢` 10×10? Recommend rounded square — distinct from
+   everything else on the canvas today.
+2. **Snap radius when inserting onto a cable.** ~16 px world-units feels
+   right at 1× zoom. Should it scale with zoom (visual constant) or stay
+   world-constant (gesture stays the same regardless of zoom)? Recommend
+   visual constant — divide by current zoom.
+3. **Clamp deletion when shared.** If a clamp is used by 4 cables and m
+   clicks "Delete clamp", do we (a) refuse with a "still in use" prompt,
+   (b) cascade-remove from all 4 cables, or (c) cascade silently? Current
+   draft says cascade silently. Worth a confirmation?
+4. **Bundle stripe order.** Cable-type id is stable but arbitrary; visual
+   order on a thick line affects readability. Order by stripe-count
+   (Power first if 3 Power + 1 USB), or by cable-type-id (deterministic
+   but unrelated to importance)? Recommend by-count, ties broken by id.
+5. **Solver respect for existing routing.** When m re-runs Solve after
+   hand-routing, should the solver preserve existing clamp routing on
+   user-owned (`auto=0`) cables? Auto cables are wiped + rebuilt, so
+   their clamps disappear with them — that's expected. But manual cables
+   with clamps should clearly keep them. Confirm.
+
+### 11.10 Slice plan (post-design)
+
+1. Schema migration + tx-aware store helpers (Create/Update/DeleteClamp,
+   AttachClampToCable, DetachClampFromCable, ReorderClamps).
+2. HTTP endpoints + snapshot extension.
+3. Frontend: clamp render + + Clamp tool + canvas placement (no
+   cable attach yet).
+4. Cable polyline render via clamps, mid-segment drag-to-clamp,
+   clamp inspector.
+5. Shared-segment bundle visualisation (gradient stripe + count badge).
+6. Export pipeline extension — mxdrw arrows with mid-points + clamp
+   diamonds. Bundle viz stays viewer-only.
+
+---
+
+DESIGN v5 READY FOR REVIEW

go.mod

@@ -1,4 +1,4 @@
-module mgit.msbls.de/m/mcables
+module mgit.msbls.de/m/cablegui
 
 go 1.25.5
 

internal/db/clamps.go

@@ -0,0 +1,351 @@
+package db
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// ClampCreate is the create-shape for a new clamp.
+type ClampCreate struct {
+	X       float64
+	Y       float64
+	Label   string
+	FrameID *int64
+}
+
+// ClampUpdate is the partial-update shape.
+type ClampUpdate struct {
+	X       *float64
+	Y       *float64
+	Label   *string
+	// FrameID tri-state: nil = leave alone; non-nil pointer to nil ptr
+	// would be ambiguous, so we use FrameRef like devices.
+	FrameID FrameRef
+}
+
+// CreateClamp inserts a new clamp inside a project.
+func (s *Store) CreateClamp(projectID int64, c ClampCreate) (*Clamp, error) {
+	if _, err := s.GetProject(projectID); err != nil {
+		return nil, err
+	}
+	if c.FrameID != nil {
+		if _, err := s.GetFrame(projectID, *c.FrameID); err != nil {
+			return nil, fmt.Errorf("%w: frame_id: %v", ErrInvalidInput, err)
+		}
+	}
+	res, err := s.db.Exec(
+		`INSERT INTO clamps (project_id, x, y, label, frame_id)
+		 VALUES (?, ?, ?, ?, ?)`,
+		projectID, c.X, c.Y, strings.TrimSpace(c.Label), nullableInt64(c.FrameID),
+	)
+	if err != nil {
+		return nil, mapWriteErr(err)
+	}
+	id, _ := res.LastInsertId()
+	return s.GetClamp(projectID, id)
+}
+
+// GetClamp returns a single clamp scoped to the project.
+func (s *Store) GetClamp(projectID, id int64) (*Clamp, error) {
+	var c Clamp
+	var frame sql.NullInt64
+	var ex sql.NullString
+	err := s.db.QueryRow(
+		`SELECT id, project_id, x, y, label, frame_id, excalidraw_id, created_at, updated_at
+		 FROM clamps WHERE id = ? AND project_id = ?`, id, projectID,
+	).Scan(&c.ID, &c.ProjectID, &c.X, &c.Y, &c.Label, &frame, &ex, &c.CreatedAt, &c.UpdatedAt)
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+	if frame.Valid {
+		v := frame.Int64
+		c.FrameID = &v
+	}
+	if ex.Valid {
+		c.ExcalidrawID = &ex.String
+	}
+	return &c, nil
+}
+
+// ListClamps returns every clamp in a project, ordered by id.
+func (s *Store) ListClamps(projectID int64) ([]Clamp, error) {
+	rows, err := s.db.Query(
+		`SELECT id, project_id, x, y, label, frame_id, excalidraw_id, created_at, updated_at
+		 FROM clamps WHERE project_id = ? ORDER BY id`, projectID,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	out := []Clamp{}
+	for rows.Next() {
+		var c Clamp
+		var frame sql.NullInt64
+		var ex sql.NullString
+		if err := rows.Scan(&c.ID, &c.ProjectID, &c.X, &c.Y, &c.Label, &frame, &ex, &c.CreatedAt, &c.UpdatedAt); err != nil {
+			return nil, err
+		}
+		if frame.Valid {
+			v := frame.Int64
+			c.FrameID = &v
+		}
+		if ex.Valid {
+			c.ExcalidrawID = &ex.String
+		}
+		out = append(out, c)
+	}
+	return out, rows.Err()
+}
+
+// UpdateClamp applies a partial update.
+func (s *Store) UpdateClamp(projectID, id int64, u ClampUpdate) (*Clamp, error) {
+	cur, err := s.GetClamp(projectID, id)
+	if err != nil {
+		return nil, err
+	}
+	if u.X != nil {
+		cur.X = *u.X
+	}
+	if u.Y != nil {
+		cur.Y = *u.Y
+	}
+	if u.Label != nil {
+		cur.Label = strings.TrimSpace(*u.Label)
+	}
+	if u.FrameID.Set {
+		if u.FrameID.ID == nil {
+			cur.FrameID = nil
+		} else {
+			if _, err := s.GetFrame(projectID, *u.FrameID.ID); err != nil {
+				return nil, fmt.Errorf("%w: frame_id: %v", ErrInvalidInput, err)
+			}
+			id := *u.FrameID.ID
+			cur.FrameID = &id
+		}
+	}
+	if _, err := s.db.Exec(
+		`UPDATE clamps SET x = ?, y = ?, label = ?, frame_id = ?, updated_at = datetime('now')
+		 WHERE id = ? AND project_id = ?`,
+		cur.X, cur.Y, cur.Label, nullableInt64(cur.FrameID), id, projectID,
+	); err != nil {
+		return nil, mapWriteErr(err)
+	}
+	return s.GetClamp(projectID, id)
+}
+
+// DeleteClamp removes a clamp. cable_clamps rows cascade.
+func (s *Store) DeleteClamp(projectID, id int64) error {
+	res, err := s.db.Exec(`DELETE FROM clamps WHERE id = ? AND project_id = ?`, id, projectID)
+	if err != nil {
+		return mapWriteErr(err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return ErrNotFound
+	}
+	return nil
+}
+
+// ListCableClamps returns every (cable_id, clamp_id, ord) row in a
+// project, joined through cables to scope by project_id.
+func (s *Store) ListCableClamps(projectID int64) ([]CableClamp, error) {
+	rows, err := s.db.Query(
+		`SELECT cc.cable_id, cc.clamp_id, cc.ord
+		 FROM cable_clamps cc
+		 JOIN cables c ON c.id = cc.cable_id
+		 WHERE c.project_id = ?
+		 ORDER BY cc.cable_id, cc.ord`, projectID,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	out := []CableClamp{}
+	for rows.Next() {
+		var cc CableClamp
+		if err := rows.Scan(&cc.CableID, &cc.ClampID, &cc.Ord); err != nil {
+			return nil, err
+		}
+		out = append(out, cc)
+	}
+	return out, rows.Err()
+}
+
+// ListClampsForCable returns the clamps on a cable in ord sequence.
+func (s *Store) ListClampsForCable(projectID, cableID int64) ([]CableClamp, error) {
+	if _, err := s.GetCable(projectID, cableID); err != nil {
+		return nil, err
+	}
+	rows, err := s.db.Query(
+		`SELECT cable_id, clamp_id, ord
+		 FROM cable_clamps WHERE cable_id = ? ORDER BY ord`, cableID,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	out := []CableClamp{}
+	for rows.Next() {
+		var cc CableClamp
+		if err := rows.Scan(&cc.CableID, &cc.ClampID, &cc.Ord); err != nil {
+			return nil, err
+		}
+		out = append(out, cc)
+	}
+	return out, rows.Err()
+}
+
+// AttachClampToCable inserts a (cable, clamp) row. If `ord` is 0, the
+// clamp is appended at the end. Otherwise existing rows at or after
+// `ord` shift up by 1 to make room.
+func (s *Store) AttachClampToCable(projectID, cableID, clampID int64, ord int) (*CableClamp, error) {
+	if _, err := s.GetCable(projectID, cableID); err != nil {
+		return nil, err
+	}
+	if _, err := s.GetClamp(projectID, clampID); err != nil {
+		return nil, fmt.Errorf("%w: clamp not found", ErrInvalidInput)
+	}
+	tx, err := s.db.Begin()
+	if err != nil {
+		return nil, err
+	}
+	defer tx.Rollback()
+	// Refuse loops — UNIQUE (cable_id, clamp_id) enforces this, but a
+	// pre-check gives a clearer error.
+	var exists int
+	if err := tx.QueryRow(
+		`SELECT COUNT(*) FROM cable_clamps WHERE cable_id = ? AND clamp_id = ?`,
+		cableID, clampID,
+	).Scan(&exists); err != nil {
+		return nil, err
+	}
+	if exists > 0 {
+		return nil, fmt.Errorf("%w: clamp %d already on cable %d", ErrConflict, clampID, cableID)
+	}
+	var maxOrd sql.NullInt64
+	if err := tx.QueryRow(
+		`SELECT MAX(ord) FROM cable_clamps WHERE cable_id = ?`, cableID,
+	).Scan(&maxOrd); err != nil {
+		return nil, err
+	}
+	current := 0
+	if maxOrd.Valid {
+		current = int(maxOrd.Int64)
+	}
+	if ord <= 0 || ord > current+1 {
+		ord = current + 1
+	} else if ord <= current {
+		// Shift existing rows at ord..current up by 1 to free the slot.
+		// SQLite UPDATE doesn't support ORDER BY (no UPDATE-with-temp
+		// trick available), so a single `ord = ord + 1` would collide
+		// with the UNIQUE (cable_id, ord) constraint during the bulk
+		// update. Two-pass avoids the conflict: bump to a high offset
+		// first, then settle back to ord+1.
+		if _, err := tx.Exec(
+			`UPDATE cable_clamps SET ord = ord + 10000
+			 WHERE cable_id = ? AND ord >= ?`, cableID, ord,
+		); err != nil {
+			return nil, mapWriteErr(err)
+		}
+		if _, err := tx.Exec(
+			`UPDATE cable_clamps SET ord = ord - 10000 + 1
+			 WHERE cable_id = ? AND ord >= ?`, cableID, 10000+ord,
+		); err != nil {
+			return nil, mapWriteErr(err)
+		}
+	}
+	if _, err := tx.Exec(
+		`INSERT INTO cable_clamps (cable_id, clamp_id, ord) VALUES (?, ?, ?)`,
+		cableID, clampID, ord,
+	); err != nil {
+		return nil, mapWriteErr(err)
+	}
+	if err := tx.Commit(); err != nil {
+		return nil, err
+	}
+	return &CableClamp{CableID: cableID, ClampID: clampID, Ord: ord}, nil
+}
+
+// DetachClampFromCable removes a clamp from a cable's polyline. The
+// trailing rows close up to keep `ord` contiguous.
+func (s *Store) DetachClampFromCable(projectID, cableID, clampID int64) error {
+	if _, err := s.GetCable(projectID, cableID); err != nil {
+		return err
+	}
+	tx, err := s.db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	var removed sql.NullInt64
+	if err := tx.QueryRow(
+		`SELECT ord FROM cable_clamps WHERE cable_id = ? AND clamp_id = ?`,
+		cableID, clampID,
+	).Scan(&removed); err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return ErrNotFound
+		}
+		return err
+	}
+	if _, err := tx.Exec(
+		`DELETE FROM cable_clamps WHERE cable_id = ? AND clamp_id = ?`,
+		cableID, clampID,
+	); err != nil {
+		return mapWriteErr(err)
+	}
+	// Close the gap: anyone with ord > removed slides down by 1.
+	if _, err := tx.Exec(
+		`UPDATE cable_clamps SET ord = ord - 1
+		 WHERE cable_id = ? AND ord > ?`, cableID, removed.Int64,
+	); err != nil {
+		return mapWriteErr(err)
+	}
+	return tx.Commit()
+}
+
+// ReorderCableClamps replaces the whole clamp sequence on a cable with
+// the given clamp IDs, in order. Every member of clampIDs must already
+// be a valid clamp in the same project; duplicates → ErrConflict.
+func (s *Store) ReorderCableClamps(projectID, cableID int64, clampIDs []int64) ([]CableClamp, error) {
+	if _, err := s.GetCable(projectID, cableID); err != nil {
+		return nil, err
+	}
+	seen := map[int64]bool{}
+	for _, cid := range clampIDs {
+		if seen[cid] {
+			return nil, fmt.Errorf("%w: duplicate clamp %d", ErrConflict, cid)
+		}
+		seen[cid] = true
+		if _, err := s.GetClamp(projectID, cid); err != nil {
+			return nil, fmt.Errorf("%w: clamp %d not in project", ErrInvalidInput, cid)
+		}
+	}
+	tx, err := s.db.Begin()
+	if err != nil {
+		return nil, err
+	}
+	defer tx.Rollback()
+	if _, err := tx.Exec(`DELETE FROM cable_clamps WHERE cable_id = ?`, cableID); err != nil {
+		return nil, mapWriteErr(err)
+	}
+	out := make([]CableClamp, 0, len(clampIDs))
+	for i, cid := range clampIDs {
+		ord := i + 1
+		if _, err := tx.Exec(
+			`INSERT INTO cable_clamps (cable_id, clamp_id, ord) VALUES (?, ?, ?)`,
+			cableID, cid, ord,
+		); err != nil {
+			return nil, mapWriteErr(err)
+		}
+		out = append(out, CableClamp{CableID: cableID, ClampID: cid, Ord: ord})
+	}
+	if err := tx.Commit(); err != nil {
+		return nil, err
+	}
+	return out, nil
+}

internal/db/clamps_test.go

@@ -0,0 +1,188 @@
+package db
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestCreateClamp_Basic(t *testing.T) {
+	s := newTestStore(t)
+	p, _ := s.CreateProject("LOFT", "", "")
+	c, err := s.CreateClamp(p.ID, ClampCreate{X: 100, Y: 200, Label: "trunk-1"})
+	if err != nil {
+		t.Fatalf("create: %v", err)
+	}
+	if c.X != 100 || c.Y != 200 || c.Label != "trunk-1" {
+		t.Errorf("bad shape: %+v", c)
+	}
+	if c.ProjectID != p.ID {
+		t.Errorf("project_id mismatch: got %d, want %d", c.ProjectID, p.ID)
+	}
+}
+
+func TestUpdateClamp_PositionAndLabel(t *testing.T) {
+	s := newTestStore(t)
+	p, _ := s.CreateProject("LOFT", "", "")
+	c, _ := s.CreateClamp(p.ID, ClampCreate{X: 0, Y: 0})
+	nx, ny := 50.0, 75.0
+	lbl := "renamed"
+	upd, err := s.UpdateClamp(p.ID, c.ID, ClampUpdate{X: &nx, Y: &ny, Label: &lbl})
+	if err != nil {
+		t.Fatalf("update: %v", err)
+	}
+	if upd.X != 50 || upd.Y != 75 || upd.Label != "renamed" {
+		t.Errorf("update didn't take: %+v", upd)
+	}
+}
+
+func TestDeleteClamp_CascadesToCableClamps(t *testing.T) {
+	s := newTestStore(t)
+	p, _ := s.CreateProject("LOFT", "", "")
+	pcT := builtInTypeID(t, s, "PC")
+	a, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "A", TypeID: &pcT, X: 0, Y: 0, Width: 100, Height: 35})
+	b, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "B", TypeID: &pcT, X: 200, Y: 0, Width: 100, Height: 35})
+	cab, _ := s.CreateCable(p.ID, CableCreate{TypeID: 1,
+		From: CableEndpoint{DeviceID: &a.ID}, To: CableEndpoint{DeviceID: &b.ID}})
+	cl, _ := s.CreateClamp(p.ID, ClampCreate{X: 100, Y: 50})
+	if _, err := s.AttachClampToCable(p.ID, cab.ID, cl.ID, 0); err != nil {
+		t.Fatalf("attach: %v", err)
+	}
+	if err := s.DeleteClamp(p.ID, cl.ID); err != nil {
+		t.Fatalf("delete: %v", err)
+	}
+	rows, _ := s.ListClampsForCable(p.ID, cab.ID)
+	if len(rows) != 0 {
+		t.Errorf("cable_clamps not cleared: %+v", rows)
+	}
+}
+
+func TestAttachClampToCable_AppendsAndOrders(t *testing.T) {
+	s := newTestStore(t)
+	p, _ := s.CreateProject("LOFT", "", "")
+	pcT := builtInTypeID(t, s, "PC")
+	a, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "A", TypeID: &pcT, X: 0, Y: 0, Width: 100, Height: 35})
+	b, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "B", TypeID: &pcT, X: 200, Y: 0, Width: 100, Height: 35})
+	cab, _ := s.CreateCable(p.ID, CableCreate{TypeID: 1,
+		From: CableEndpoint{DeviceID: &a.ID}, To: CableEndpoint{DeviceID: &b.ID}})
+	c1, _ := s.CreateClamp(p.ID, ClampCreate{X: 50, Y: 0})
+	c2, _ := s.CreateClamp(p.ID, ClampCreate{X: 100, Y: 0})
+	c3, _ := s.CreateClamp(p.ID, ClampCreate{X: 150, Y: 0})
+	cc1, _ := s.AttachClampToCable(p.ID, cab.ID, c1.ID, 0)
+	cc2, _ := s.AttachClampToCable(p.ID, cab.ID, c2.ID, 0)
+	cc3, _ := s.AttachClampToCable(p.ID, cab.ID, c3.ID, 0)
+	if cc1.Ord != 1 || cc2.Ord != 2 || cc3.Ord != 3 {
+		t.Errorf("ord sequence wrong: %d, %d, %d", cc1.Ord, cc2.Ord, cc3.Ord)
+	}
+}
+
+func TestAttachClampToCable_InsertShiftsExisting(t *testing.T) {
+	s := newTestStore(t)
+	p, _ := s.CreateProject("LOFT", "", "")
+	pcT := builtInTypeID(t, s, "PC")
+	a, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "A", TypeID: &pcT, X: 0, Y: 0, Width: 100, Height: 35})
+	b, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "B", TypeID: &pcT, X: 200, Y: 0, Width: 100, Height: 35})
+	cab, _ := s.CreateCable(p.ID, CableCreate{TypeID: 1,
+		From: CableEndpoint{DeviceID: &a.ID}, To: CableEndpoint{DeviceID: &b.ID}})
+	c1, _ := s.CreateClamp(p.ID, ClampCreate{X: 50, Y: 0})
+	c2, _ := s.CreateClamp(p.ID, ClampCreate{X: 100, Y: 0})
+	c3, _ := s.CreateClamp(p.ID, ClampCreate{X: 150, Y: 0})
+	_, _ = s.AttachClampToCable(p.ID, cab.ID, c1.ID, 0) // ord=1
+	_, _ = s.AttachClampToCable(p.ID, cab.ID, c2.ID, 0) // ord=2
+	// Insert c3 between c1 and c2 → c3 gets ord=2, old c2 bumps to 3.
+	if _, err := s.AttachClampToCable(p.ID, cab.ID, c3.ID, 2); err != nil {
+		t.Fatalf("attach mid: %v", err)
+	}
+	got, _ := s.ListClampsForCable(p.ID, cab.ID)
+	if len(got) != 3 {
+		t.Fatalf("len = %d, want 3: %+v", len(got), got)
+	}
+	want := []struct{ id int64; ord int }{
+		{c1.ID, 1}, {c3.ID, 2}, {c2.ID, 3},
+	}
+	for i, w := range want {
+		if got[i].ClampID != w.id || got[i].Ord != w.ord {
+			t.Errorf("[%d] got %+v, want clamp=%d ord=%d", i, got[i], w.id, w.ord)
+		}
+	}
+}
+
+func TestAttachClampToCable_DuplicateRejected(t *testing.T) {
+	s := newTestStore(t)
+	p, _ := s.CreateProject("LOFT", "", "")
+	pcT := builtInTypeID(t, s, "PC")
+	a, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "A", TypeID: &pcT, X: 0, Y: 0, Width: 100, Height: 35})
+	b, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "B", TypeID: &pcT, X: 200, Y: 0, Width: 100, Height: 35})
+	cab, _ := s.CreateCable(p.ID, CableCreate{TypeID: 1,
+		From: CableEndpoint{DeviceID: &a.ID}, To: CableEndpoint{DeviceID: &b.ID}})
+	c1, _ := s.CreateClamp(p.ID, ClampCreate{X: 50, Y: 0})
+	_, _ = s.AttachClampToCable(p.ID, cab.ID, c1.ID, 0)
+	if _, err := s.AttachClampToCable(p.ID, cab.ID, c1.ID, 0); !errors.Is(err, ErrConflict) {
+		t.Errorf("duplicate err = %v, want ErrConflict", err)
+	}
+}
+
+func TestDetachClampFromCable_ClosesGap(t *testing.T) {
+	s := newTestStore(t)
+	p, _ := s.CreateProject("LOFT", "", "")
+	pcT := builtInTypeID(t, s, "PC")
+	a, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "A", TypeID: &pcT, X: 0, Y: 0, Width: 100, Height: 35})
+	b, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "B", TypeID: &pcT, X: 200, Y: 0, Width: 100, Height: 35})
+	cab, _ := s.CreateCable(p.ID, CableCreate{TypeID: 1,
+		From: CableEndpoint{DeviceID: &a.ID}, To: CableEndpoint{DeviceID: &b.ID}})
+	c1, _ := s.CreateClamp(p.ID, ClampCreate{X: 50, Y: 0})
+	c2, _ := s.CreateClamp(p.ID, ClampCreate{X: 100, Y: 0})
+	c3, _ := s.CreateClamp(p.ID, ClampCreate{X: 150, Y: 0})
+	_, _ = s.AttachClampToCable(p.ID, cab.ID, c1.ID, 0)
+	_, _ = s.AttachClampToCable(p.ID, cab.ID, c2.ID, 0)
+	_, _ = s.AttachClampToCable(p.ID, cab.ID, c3.ID, 0)
+	if err := s.DetachClampFromCable(p.ID, cab.ID, c2.ID); err != nil {
+		t.Fatalf("detach: %v", err)
+	}
+	got, _ := s.ListClampsForCable(p.ID, cab.ID)
+	if len(got) != 2 {
+		t.Fatalf("len = %d, want 2", len(got))
+	}
+	if got[0].ClampID != c1.ID || got[0].Ord != 1 {
+		t.Errorf("[0] = %+v", got[0])
+	}
+	if got[1].ClampID != c3.ID || got[1].Ord != 2 {
+		t.Errorf("[1] = %+v", got[1])
+	}
+}
+
+func TestReorderCableClamps_FullReplace(t *testing.T) {
+	s := newTestStore(t)
+	p, _ := s.CreateProject("LOFT", "", "")
+	pcT := builtInTypeID(t, s, "PC")
+	a, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "A", TypeID: &pcT, X: 0, Y: 0, Width: 100, Height: 35})
+	b, _ := s.CreateDevice(p.ID, DeviceCreate{Name: "B", TypeID: &pcT, X: 200, Y: 0, Width: 100, Height: 35})
+	cab, _ := s.CreateCable(p.ID, CableCreate{TypeID: 1,
+		From: CableEndpoint{DeviceID: &a.ID}, To: CableEndpoint{DeviceID: &b.ID}})
+	c1, _ := s.CreateClamp(p.ID, ClampCreate{X: 50, Y: 0})
+	c2, _ := s.CreateClamp(p.ID, ClampCreate{X: 100, Y: 0})
+	c3, _ := s.CreateClamp(p.ID, ClampCreate{X: 150, Y: 0})
+	if _, err := s.ReorderCableClamps(p.ID, cab.ID, []int64{c3.ID, c1.ID, c2.ID}); err != nil {
+		t.Fatalf("reorder: %v", err)
+	}
+	got, _ := s.ListClampsForCable(p.ID, cab.ID)
+	if len(got) != 3 {
+		t.Fatalf("len = %d, want 3", len(got))
+	}
+	if got[0].ClampID != c3.ID || got[1].ClampID != c1.ID || got[2].ClampID != c2.ID {
+		t.Errorf("order wrong: %+v", got)
+	}
+}
+
+func TestSnapshot_IncludesClamps(t *testing.T) {
+	s := newTestStore(t)
+	p, _ := s.CreateProject("LOFT", "", "")
+	_, _ = s.CreateClamp(p.ID, ClampCreate{X: 10, Y: 20})
+	_, _ = s.CreateClamp(p.ID, ClampCreate{X: 30, Y: 40})
+	snap, err := s.Snapshot(p.ID)
+	if err != nil {
+		t.Fatalf("snapshot: %v", err)
+	}
+	if len(snap.Clamps) != 2 {
+		t.Errorf("clamps in snapshot = %d, want 2", len(snap.Clamps))
+	}
+}

internal/db/db.go

@@ -1,4 +1,4 @@
-// Package db owns SQLite access for mCables: migrations runner + the
+// Package db owns SQLite access for CableGUI: migrations runner + the
 // query layer (store.go). The Store wraps a *sql.DB with helpers; tests
 // and the HTTP layer take a *Store, never a raw *sql.DB.
 package db

internal/db/excalidraw_ids.go

@@ -12,7 +12,7 @@ import (
 // Caller passes one map per kind; keys are the in-project row ids,
 // values are the 21-char Excalidraw element ids the exporter minted.
 func (s *Store) PersistExcalidrawIDs(projectID int64,
-	frames, devices, ports, ios, cables map[int64]string,
+	frames, devices, ports, ios, cables, clamps map[int64]string,
 ) error {
 	tx, err := s.db.Begin()
 	if err != nil {
@@ -35,6 +35,9 @@ func (s *Store) PersistExcalidrawIDs(projectID int64,
 	if err := updateExIDs(tx, "cables", projectID, cables); err != nil {
 		return err
 	}
+	if err := updateExIDs(tx, "clamps", projectID, clamps); err != nil {
+		return err
+	}
 	return tx.Commit()
 }
 

internal/db/migrations/001_init.sql

@@ -1,4 +1,4 @@
--- mCables v3 initial schema. See docs/design.md §2.
+-- CableGUI v3 initial schema. See docs/design.md §2.
 
 -- A project IS a drawing. LOFT and OFFICE are separate projects.
 -- One project ↔ one .excalidraw file in mExDraw.

internal/db/migrations/002_device_catalog.sql

@@ -1,4 +1,4 @@
--- mCables v4 device-type catalog. See docs/design.md §2.1 + §2.2.
+-- CableGUI v4 device-type catalog. See docs/design.md §2.1 + §2.2.
 
 -- v4 — device-type catalog. Built-in types live globally (project_id NULL).
 -- Per-project custom types use project_id = X.

internal/db/migrations/003_connection_requirements.sql

@@ -1,4 +1,4 @@
--- mCables v4.1 connection requirements + solver-owned cable flag.
+-- CableGUI v4.1 connection requirements + solver-owned cable flag.
 -- See docs/design.md §2.1 + §2 connection_requirements + §5b.3.
 
 -- The solver's input: "device A must connect to device B via cable type T".

internal/db/migrations/004_setup_templates.sql

@@ -1,4 +1,4 @@
--- mCables v4.1 setup templates. See docs/design.md §2.4.
+-- CableGUI v4.1 setup templates. See docs/design.md §2.4.
 --
 -- A template is a named recipe of (device_types + requirements) that
 -- bootstraps a project from blank to solver-ready in one apply call.

internal/db/migrations/005_catalog_power.sql

@@ -1,4 +1,4 @@
--- mCables v5 — catalog: power-distribution devices.
+-- CableGUI v5 — catalog: power-distribution devices.
 -- Adds 5 built-in device_types (project_id NULL, built_in=1).
 --
 -- Multi-plug N exposes Power × (N+1) ports — one input + N outputs. The

internal/db/migrations/006_fix_power_hubs.sql

@@ -1,4 +1,4 @@
--- mCables v6 — fix IOx-* and Multi-plug-* + Wifi-plug port profiles.
+-- CableGUI v6 — fix IOx-* and Multi-plug-* + Wifi-plug port profiles.
 --
 -- v4 seeded the IOx-3 / IOx-6 / IOx-8 as USB hubs (Power × 1 + USB × N),
 -- but m's physical IOx-* devices are power strips (1 power input on

internal/db/migrations/007_clamps.sql

@@ -0,0 +1,31 @@
+-- CableGUI v5 — cable routing via clamps. See docs/design.md §11.
+--
+-- A clamp is a physical anchor placed on the canvas. A cable's polyline
+-- runs from its `from` endpoint → its clamps in `ord` sequence → its
+-- `to` endpoint. Cables that share an ordered pair of consecutive
+-- clamps are visibly bundled along that segment (computed live by the
+-- frontend; no detection pass).
+
+CREATE TABLE clamps (
+    id              INTEGER PRIMARY KEY,
+    project_id      INTEGER NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
+    x               REAL NOT NULL,
+    y               REAL NOT NULL,
+    label           TEXT NOT NULL DEFAULT '',
+    frame_id        INTEGER REFERENCES frames(id) ON DELETE SET NULL,
+    excalidraw_id   TEXT,
+    created_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    UNIQUE (project_id, excalidraw_id)
+);
+CREATE INDEX clamps_project_idx ON clamps(project_id);
+CREATE INDEX clamps_frame_idx   ON clamps(frame_id);
+
+CREATE TABLE cable_clamps (
+    cable_id        INTEGER NOT NULL REFERENCES cables(id) ON DELETE CASCADE,
+    clamp_id        INTEGER NOT NULL REFERENCES clamps(id) ON DELETE CASCADE,
+    ord             INTEGER NOT NULL,            -- 1-based along from→to
+    PRIMARY KEY (cable_id, ord),
+    UNIQUE (cable_id, clamp_id)
+);
+CREATE INDEX cable_clamps_clamp_idx ON cable_clamps(clamp_id);

internal/db/models.go

@@ -220,4 +220,29 @@ type Snapshot struct {
 	Bundles                []Bundle                `json:"bundles"`
 	CableTypes             []CableType             `json:"cable_types"`
 	ConnectionRequirements []ConnectionRequirement `json:"connection_requirements"`
+	Clamps                 []Clamp                 `json:"clamps"`
+	CableClamps            []CableClamp            `json:"cable_clamps"`
+}
+
+// Clamp is a routing anchor on the canvas. Cables route through clamps
+// in `ord` sequence (see cable_clamps), giving m a physical handle on
+// where bundles converge.
+type Clamp struct {
+	ID           int64   `json:"id"`
+	ProjectID    int64   `json:"project_id"`
+	X            float64 `json:"x"`
+	Y            float64 `json:"y"`
+	Label        string  `json:"label"`
+	FrameID      *int64  `json:"frame_id"`
+	ExcalidrawID *string `json:"excalidraw_id,omitempty"`
+	CreatedAt    string  `json:"created_at"`
+	UpdatedAt    string  `json:"updated_at"`
+}
+
+// CableClamp is one (cable, clamp, ord) row. Ord is 1-based along the
+// cable's from→to direction.
+type CableClamp struct {
+	CableID int64 `json:"cable_id"`
+	ClampID int64 `json:"clamp_id"`
+	Ord     int   `json:"ord"`
 }

internal/db/store.go

@@ -187,6 +187,14 @@ func (s *Store) Snapshot(id int64) (*Snapshot, error) {
 	if err != nil {
 		return nil, err
 	}
+	clamps, err := s.ListClamps(id)
+	if err != nil {
+		return nil, err
+	}
+	cableClamps, err := s.ListCableClamps(id)
+	if err != nil {
+		return nil, err
+	}
 	return &Snapshot{
 		Project:                *p,
 		Frames:                 frames,
@@ -197,6 +205,8 @@ func (s *Store) Snapshot(id int64) (*Snapshot, error) {
 		Bundles:                bundles,
 		CableTypes:             types,
 		ConnectionRequirements: reqs,
+		Clamps:                 clamps,
+		CableClamps:            cableClamps,
 	}, nil
 }
 

internal/exporter/exporter.go

@@ -11,8 +11,9 @@ import (
 	"encoding/json"
 	"fmt"
 	"math/big"
+	"sort"
 
-	"mgit.msbls.de/m/mcables/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/db"
 )
 
 // Scene is the top-level Excalidraw file format. Keys mirror what the
@@ -114,6 +115,7 @@ type IDAssignment struct {
 	Ports     map[int64]string `json:"ports"`
 	IOMarkers map[int64]string `json:"io_markers"`
 	Cables    map[int64]string `json:"cables"`
+	Clamps    map[int64]string `json:"clamps"`
 }
 
 // BuildScene transforms a project snapshot into an Excalidraw Scene +
@@ -132,6 +134,7 @@ func BuildScene(snap *db.Snapshot, nowMilli int64, genID func() string) (*Scene,
 		Ports:     map[int64]string{},
 		IOMarkers: map[int64]string{},
 		Cables:    map[int64]string{},
+		Clamps:    map[int64]string{},
 	}
 	// idFor: reuse the existing excalidraw_id if present, else mint one.
 	idFor := func(existing *string) string {
@@ -381,6 +384,58 @@ func BuildScene(snap *db.Snapshot, nowMilli int64, genID func() string) (*Scene,
 		})
 	}
 
+	// Clamps — small grey rounded squares (v5 §11.7). Distinct from the
+	// red IO marker diamonds so m can tell routing anchors from wall
+	// outlets at a glance.
+	const clampSize = 12.0
+	for _, cl := range snap.Clamps {
+		elID := idFor(cl.ExcalidrawID)
+		a.Clamps[cl.ID] = elID
+		var frameRef *string
+		if cl.FrameID != nil {
+			if v, ok := frameElID[*cl.FrameID]; ok {
+				frameRef = &v
+			}
+		}
+		els = append(els, Element{
+			ID:              elID,
+			Type:            "rectangle",
+			X:               cl.X - clampSize/2,
+			Y:               cl.Y - clampSize/2,
+			Width:           clampSize,
+			Height:          clampSize,
+			StrokeColor:     "#555555",
+			BackgroundColor: "#888888",
+			FillStyle:       "solid",
+			StrokeWidth:     1,
+			StrokeStyle:     "solid",
+			Roughness:       0,
+			Opacity:         100,
+			GroupIDs:        []string{},
+			FrameID:         frameRef,
+			Roundness:       &Roundness{Type: 3},
+			Seed:            randInt(),
+			Version:         1,
+			VersionNonce:    randInt(),
+			Updated:         nowMilli,
+		})
+	}
+
+	// Pre-group cable_clamps by cable for the arrow mid-points pass.
+	clampsByCable := map[int64][]db.CableClamp{}
+	for _, cc := range snap.CableClamps {
+		clampsByCable[cc.CableID] = append(clampsByCable[cc.CableID], cc)
+	}
+	for _, arr := range clampsByCable {
+		// Already sorted by ListCableClamps (ORDER BY cable_id, ord),
+		// but defend against unsorted inputs.
+		sort.Slice(arr, func(i, j int) bool { return arr[i].Ord < arr[j].Ord })
+	}
+	clampPos := map[int64][2]float64{}
+	for _, cl := range snap.Clamps {
+		clampPos[cl.ID] = [2]float64{cl.X, cl.Y}
+	}
+
 	// Cables — arrows with startBinding/endBinding to the port / device /
 	// IO marker excalidraw_ids. Endpoint anchors (the visible "from" /
 	// "to" points) come from the same anchor logic the canvas uses.
@@ -403,6 +458,18 @@ func BuildScene(snap *db.Snapshot, nowMilli int64, genID func() string) (*Scene,
 		}
 		startArr := ""
 		endArr := "arrow"
+		// Excalidraw arrow `points` is relative to (X, Y). We anchor at
+		// the from-point, so vertex 0 is always (0, 0). Mid-vertices
+		// (clamps) and the final to-vertex are offsets from there.
+		pts := [][2]float64{{0, 0}}
+		for _, cc := range clampsByCable[c.ID] {
+			pos, ok := clampPos[cc.ClampID]
+			if !ok {
+				continue
+			}
+			pts = append(pts, [2]float64{pos[0] - fromAnchor[0], pos[1] - fromAnchor[1]})
+		}
+		pts = append(pts, [2]float64{toAnchor[0] - fromAnchor[0], toAnchor[1] - fromAnchor[1]})
 		els = append(els, Element{
 			ID:              elID,
 			Type:            "arrow",
@@ -422,7 +489,7 @@ func BuildScene(snap *db.Snapshot, nowMilli int64, genID func() string) (*Scene,
 			Version:         1,
 			VersionNonce:    randInt(),
 			Updated:         nowMilli,
-			Points:          [][2]float64{{0, 0}, {toAnchor[0] - fromAnchor[0], toAnchor[1] - fromAnchor[1]}},
+			Points:          pts,
 			StartArrowhead:  &startArr,
 			EndArrowhead:    &endArr,
 			StartBinding:    bindingPtr(fromRef),
@@ -470,7 +537,7 @@ func BuildScene(snap *db.Snapshot, nowMilli int64, genID func() string) (*Scene,
 	scene := &Scene{
 		Type:     "excalidraw",
 		Version:  2,
-		Source:   "mcables",
+		Source:   "cablegui",
 		Elements: els,
 		AppState: AppState{
 			GridSize:       nil,

internal/exporter/exporter_test.go

@@ -5,7 +5,7 @@ import (
 	"strings"
 	"testing"
 
-	"mgit.msbls.de/m/mcables/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/db"
 )
 
 // deterministic id generator for tests
@@ -137,6 +137,66 @@ func TestBuildScene_BundlesIgnored(t *testing.T) {
 	}
 }
 
+func TestBuildScene_ClampsRenderAsRectangles(t *testing.T) {
+	snap := sampleSnapshot()
+	snap.Clamps = []db.Clamp{
+		{ID: 1, ProjectID: 1, X: 500, Y: 300},
+		{ID: 2, ProjectID: 1, X: 550, Y: 320},
+	}
+	scene, ids := BuildScene(snap, 1700000000000, newSeq())
+	if len(ids.Clamps) != 2 {
+		t.Errorf("clamp ids = %d, want 2", len(ids.Clamps))
+	}
+	clampElIDs := map[string]bool{}
+	for _, id := range ids.Clamps {
+		clampElIDs[id] = true
+	}
+	got := 0
+	for _, e := range scene.Elements {
+		if clampElIDs[e.ID] && e.Type == "rectangle" {
+			got++
+		}
+	}
+	if got != 2 {
+		t.Errorf("clamp rectangle elements = %d, want 2", got)
+	}
+}
+
+func TestBuildScene_ArrowPointsIncludeClamps(t *testing.T) {
+	snap := sampleSnapshot()
+	snap.Clamps = []db.Clamp{
+		{ID: 10, ProjectID: 1, X: 350, Y: 250},
+	}
+	snap.CableClamps = []db.CableClamp{
+		{CableID: 1000, ClampID: 10, Ord: 1},
+	}
+	scene, _ := BuildScene(snap, 1700000000000, newSeq())
+	var arrow *Element
+	for i := range scene.Elements {
+		if scene.Elements[i].Type == "arrow" {
+			arrow = &scene.Elements[i]
+			break
+		}
+	}
+	if arrow == nil {
+		t.Fatal("no arrow in scene")
+	}
+	if len(arrow.Points) != 3 {
+		t.Errorf("arrow points = %d, want 3 (from + clamp + to): %+v", len(arrow.Points), arrow.Points)
+	}
+	// First point is always (0, 0) by convention; middle point should
+	// equal the clamp's position relative to the arrow's anchor.
+	if arrow.Points[0][0] != 0 || arrow.Points[0][1] != 0 {
+		t.Errorf("first point = %v, want [0,0]", arrow.Points[0])
+	}
+	// Middle vertex = clamp.x - fromAnchor.x, clamp.y - fromAnchor.y.
+	// fromAnchor for port 100 = (200 + 50, 200 + 35) = (250, 235).
+	wantX, wantY := 350.0-250.0, 250.0-235.0
+	if arrow.Points[1][0] != wantX || arrow.Points[1][1] != wantY {
+		t.Errorf("mid point = %v, want [%v, %v]", arrow.Points[1], wantX, wantY)
+	}
+}
+
 func TestMarshalScene_IsJSON(t *testing.T) {
 	snap := sampleSnapshot()
 	scene, _ := BuildScene(snap, 1700000000000, newSeq())

internal/server/cables.go

@@ -5,7 +5,7 @@ import (
 	"errors"
 	"net/http"
 
-	"mgit.msbls.de/m/mcables/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/db"
 )
 
 type cableEndpointBody struct {

internal/server/clamps.go

@@ -0,0 +1,195 @@
+package server
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+
+	"mgit.msbls.de/m/cablegui/internal/db"
+)
+
+type clampCreate struct {
+	X       float64         `json:"x"`
+	Y       float64         `json:"y"`
+	Label   string          `json:"label,omitempty"`
+	FrameID json.RawMessage `json:"frame_id,omitempty"`
+}
+
+type clampPatch struct {
+	X       *float64        `json:"x,omitempty"`
+	Y       *float64        `json:"y,omitempty"`
+	Label   *string         `json:"label,omitempty"`
+	FrameID json.RawMessage `json:"frame_id,omitempty"`
+}
+
+type cableClampAttach struct {
+	ClampID int64 `json:"clamp_id"`
+	Ord     int   `json:"ord,omitempty"`
+}
+
+type cableClampReorder struct {
+	ClampIDs []int64 `json:"clamp_ids"`
+}
+
+func (h *handlers) listClamps(w http.ResponseWriter, r *http.Request) {
+	pid, ok := parseInt64Path(r, "pid")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "pid must be a positive integer")
+		return
+	}
+	cs, err := h.store.ListClamps(pid)
+	if err != nil {
+		writeError(w, err, nil)
+		return
+	}
+	writeJSON(w, http.StatusOK, cs)
+}
+
+func (h *handlers) createClamp(w http.ResponseWriter, r *http.Request) {
+	pid, ok := parseInt64Path(r, "pid")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "pid must be a positive integer")
+		return
+	}
+	var body clampCreate
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		writeError(w, errors.Join(db.ErrInvalidInput, err), nil)
+		return
+	}
+	ref, err := parseFrameRef(body.FrameID)
+	if err != nil {
+		writeError(w, errors.Join(db.ErrInvalidInput, err), nil)
+		return
+	}
+	c, err := h.store.CreateClamp(pid, db.ClampCreate{
+		X: body.X, Y: body.Y, Label: body.Label, FrameID: ref.ID,
+	})
+	if err != nil {
+		writeError(w, err, nil)
+		return
+	}
+	writeJSON(w, http.StatusCreated, c)
+}
+
+func (h *handlers) patchClamp(w http.ResponseWriter, r *http.Request) {
+	pid, ok := parseInt64Path(r, "pid")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "pid must be a positive integer")
+		return
+	}
+	id, ok := parseInt64Path(r, "id")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "id must be a positive integer")
+		return
+	}
+	var body clampPatch
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		writeError(w, errors.Join(db.ErrInvalidInput, err), nil)
+		return
+	}
+	ref, err := parseFrameRef(body.FrameID)
+	if err != nil {
+		writeError(w, errors.Join(db.ErrInvalidInput, err), nil)
+		return
+	}
+	c, err := h.store.UpdateClamp(pid, id, db.ClampUpdate{
+		X: body.X, Y: body.Y, Label: body.Label, FrameID: ref,
+	})
+	if err != nil {
+		writeError(w, err, nil)
+		return
+	}
+	writeJSON(w, http.StatusOK, c)
+}
+
+func (h *handlers) deleteClamp(w http.ResponseWriter, r *http.Request) {
+	pid, ok := parseInt64Path(r, "pid")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "pid must be a positive integer")
+		return
+	}
+	id, ok := parseInt64Path(r, "id")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "id must be a positive integer")
+		return
+	}
+	if err := h.store.DeleteClamp(pid, id); err != nil {
+		writeError(w, err, nil)
+		return
+	}
+	w.WriteHeader(http.StatusNoContent)
+}
+
+// POST /api/projects/:pid/cables/:cid/clamps — attach a clamp to a cable.
+func (h *handlers) attachClampToCable(w http.ResponseWriter, r *http.Request) {
+	pid, ok := parseInt64Path(r, "pid")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "pid must be a positive integer")
+		return
+	}
+	cid, ok := parseInt64Path(r, "cid")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "cid must be a positive integer")
+		return
+	}
+	var body cableClampAttach
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		writeError(w, errors.Join(db.ErrInvalidInput, err), nil)
+		return
+	}
+	cc, err := h.store.AttachClampToCable(pid, cid, body.ClampID, body.Ord)
+	if err != nil {
+		writeError(w, err, nil)
+		return
+	}
+	writeJSON(w, http.StatusCreated, cc)
+}
+
+// DELETE /api/projects/:pid/cables/:cid/clamps/:cmid — detach a clamp.
+func (h *handlers) detachClampFromCable(w http.ResponseWriter, r *http.Request) {
+	pid, ok := parseInt64Path(r, "pid")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "pid must be a positive integer")
+		return
+	}
+	cid, ok := parseInt64Path(r, "cid")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "cid must be a positive integer")
+		return
+	}
+	cmid, ok := parseInt64Path(r, "cmid")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "cmid must be a positive integer")
+		return
+	}
+	if err := h.store.DetachClampFromCable(pid, cid, cmid); err != nil {
+		writeError(w, err, nil)
+		return
+	}
+	w.WriteHeader(http.StatusNoContent)
+}
+
+// PUT /api/projects/:pid/cables/:cid/clamps — replace clamp sequence.
+func (h *handlers) reorderCableClamps(w http.ResponseWriter, r *http.Request) {
+	pid, ok := parseInt64Path(r, "pid")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "pid must be a positive integer")
+		return
+	}
+	cid, ok := parseInt64Path(r, "cid")
+	if !ok {
+		writeError(w, db.ErrInvalidInput, "cid must be a positive integer")
+		return
+	}
+	var body cableClampReorder
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		writeError(w, errors.Join(db.ErrInvalidInput, err), nil)
+		return
+	}
+	out, err := h.store.ReorderCableClamps(pid, cid, body.ClampIDs)
+	if err != nil {
+		writeError(w, err, nil)
+		return
+	}
+	writeJSON(w, http.StatusOK, out)
+}

internal/server/connection_requirements.go

@@ -5,7 +5,7 @@ import (
 	"errors"
 	"net/http"
 
-	"mgit.msbls.de/m/mcables/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/db"
 )
 
 type connReqCreate struct {

internal/server/device_types.go

@@ -5,7 +5,7 @@ import (
 	"errors"
 	"net/http"
 
-	"mgit.msbls.de/m/mcables/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/db"
 )
 
 type deviceTypePortBody struct {

internal/server/export.go

@@ -12,8 +12,8 @@ import (
 	"strings"
 	"time"
 
-	"mgit.msbls.de/m/mcables/internal/db"
-	"mgit.msbls.de/m/mcables/internal/exporter"
+	"mgit.msbls.de/m/cablegui/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/exporter"
 )
 
 // syncExport runs the project's snapshot through the exporter, persists
@@ -34,7 +34,7 @@ func (h *handlers) syncExport(w http.ResponseWriter, r *http.Request) {
 	if user == "" || pass == "" {
 		writeJSON(w, http.StatusBadRequest, errorBody{
 			Error:   "MEXDRAW_USER / MEXDRAW_PASS not set",
-			Details: "Add MEXDRAW_USER and MEXDRAW_PASS to /home/m/secrets/mcables/.env on mDock and restart the container — mxdrw expects HTTP Basic Auth",
+			Details: "Add MEXDRAW_USER and MEXDRAW_PASS to /home/m/secrets/cablegui/.env on mDock and restart the container — mxdrw expects HTTP Basic Auth",
 		})
 		return
 	}
@@ -51,7 +51,7 @@ func (h *handlers) syncExport(w http.ResponseWriter, r *http.Request) {
 	// Persist the freshly-assigned ids so the next export reuses them.
 	// We pass in the full maps; PersistExcalidrawIDs is idempotent (it
 	// only updates rows whose excalidraw_id is still NULL).
-	if err := h.store.PersistExcalidrawIDs(pid, ids.Frames, ids.Devices, ids.Ports, ids.IOMarkers, ids.Cables); err != nil {
+	if err := h.store.PersistExcalidrawIDs(pid, ids.Frames, ids.Devices, ids.Ports, ids.IOMarkers, ids.Cables, ids.Clamps); err != nil {
 		writeError(w, fmt.Errorf("persist excalidraw_ids: %w", err), nil)
 		return
 	}

internal/server/frames_devices.go

@@ -5,7 +5,7 @@ import (
 	"errors"
 	"net/http"
 
-	"mgit.msbls.de/m/mcables/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/db"
 )
 
 // ---------------------------------------------------------------- frames

internal/server/handlers.go

@@ -6,7 +6,7 @@ import (
 	"net/http"
 	"strconv"
 
-	"mgit.msbls.de/m/mcables/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/db"
 )
 
 type handlers struct {

internal/server/io_markers.go

@@ -5,7 +5,7 @@ import (
 	"errors"
 	"net/http"
 
-	"mgit.msbls.de/m/mcables/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/db"
 )
 
 type ioMarkerCreate struct {

internal/server/ports.go

@@ -5,7 +5,7 @@ import (
 	"errors"
 	"net/http"
 
-	"mgit.msbls.de/m/mcables/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/db"
 )
 
 type portCreate struct {

internal/server/server.go

@@ -7,10 +7,10 @@ import (
 	"io/fs"
 	"net/http"
 
-	"mgit.msbls.de/m/mcables/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/db"
 )
 
-// New returns an http.Handler serving the mCables API at /api/ and the
+// New returns an http.Handler serving the CableGUI API at /api/ and the
 // embedded frontend at /. The frontend FS should be rooted such that
 // "index.html" is at its root.
 func New(store *db.Store, frontend fs.FS) http.Handler {
@@ -93,6 +93,15 @@ func New(store *db.Store, frontend fs.FS) http.Handler {
 	// Slice 8 — export to mxdrw.msbls.de
 	mux.HandleFunc("POST /api/projects/{pid}/sync/export", h.syncExport)
 
+	// v5 — clamps + cable routing.
+	mux.HandleFunc("GET /api/projects/{pid}/clamps", h.listClamps)
+	mux.HandleFunc("POST /api/projects/{pid}/clamps", h.createClamp)
+	mux.HandleFunc("PATCH /api/projects/{pid}/clamps/{id}", h.patchClamp)
+	mux.HandleFunc("DELETE /api/projects/{pid}/clamps/{id}", h.deleteClamp)
+	mux.HandleFunc("POST /api/projects/{pid}/cables/{cid}/clamps", h.attachClampToCable)
+	mux.HandleFunc("PUT /api/projects/{pid}/cables/{cid}/clamps", h.reorderCableClamps)
+	mux.HandleFunc("DELETE /api/projects/{pid}/cables/{cid}/clamps/{cmid}", h.detachClampFromCable)
+
 	// Frontend (embedded). Serve "/" → index.html via http.FileServerFS.
 	// Wrap in noCache so the browser revalidates with the ETag/Last-Modified
 	// the file server already emits — without this, browsers cache aggressively

internal/server/solver.go

@@ -5,7 +5,7 @@ import (
 	"errors"
 	"net/http"
 
-	"mgit.msbls.de/m/mcables/internal/db"
+	"mgit.msbls.de/m/cablegui/internal/db"
 )
 
 func (h *handlers) solve(w http.ResponseWriter, r *http.Request) {

web/static/index.html

@@ -3,12 +3,12 @@
 <head>
   <meta charset="utf-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1" />
-  <title>mCables</title>
+  <title>CableGUI</title>
   <link rel="stylesheet" href="/style.css" />
 </head>
 <body>
   <header class="topbar">
-    <span class="brand">mCables</span>
+    <span class="brand">CableGUI</span>
     <div class="project-picker">
       <label for="project-select" class="sr-only">Project</label>
       <select id="project-select" aria-label="Active project">
@@ -36,7 +36,6 @@
       <section class="legend">
         <h2 class="sidebar-heading">Cable types</h2>
         <ul id="legend-list" class="legend-list"></ul>
-        <button type="button" id="btn-add-type" class="btn btn-tiny">+ Type</button>
       </section>
       <section class="tools">
         <h2 class="sidebar-heading">Tools</h2>
@@ -44,6 +43,7 @@
           <li><button type="button" id="tool-frame"  class="btn btn-tiny" data-tool="frame">+ Frame</button></li>
           <li><button type="button" id="tool-device" class="btn btn-tiny" data-tool="device">+ Device</button></li>
           <li><button type="button" id="tool-io"     class="btn btn-tiny" data-tool="io">+ IO</button></li>
+          <li><button type="button" id="tool-clamp"  class="btn btn-tiny" data-tool="clamp" title="Click canvas to drop a clamp. Cables can then route through it.">+ Clamp</button></li>
           <li><button type="button" id="tool-req"    class="btn btn-tiny" data-tool="req">Drag req A→B</button></li>
           <li><button type="button" id="tool-cable"  class="btn btn-tiny" data-tool="cable" title="Click a port to start, then click another port / device / IO marker">Draw cable</button></li>
         </ul>
@@ -52,10 +52,13 @@
 
     <section class="canvas-wrap" aria-label="Diagram">
       <svg id="canvas" viewBox="0 0 2000 1500" preserveAspectRatio="xMidYMid meet">
+        <defs id="canvas-defs"></defs>
         <g id="canvas-frames"></g>
         <g id="canvas-devices"></g>
         <g id="canvas-ports"></g>
         <g id="canvas-cables"></g>
+        <g id="canvas-bundles"></g>
+        <g id="canvas-clamps"></g>
         <g id="canvas-io"></g>
       </svg>
       <p id="empty-hint" class="empty-hint">

web/static/main.js

@@ -1,4 +1,4 @@
-// mCables frontend entry — vanilla ES module, no build step.
+// CableGUI frontend entry — vanilla ES module, no build step.
 //
 // Slice 2 adds: frame + device rendering, +Frm/+Dev tools, drag-to-position,
 // inline naming, inspector for selection. State stays minimal: one
@@ -41,6 +41,7 @@
 const API = "/api";
 const SVG_NS = "http://www.w3.org/2000/svg";
 const IO_SIZE = 30; // diamond bounding-box side (the rotated rect's width/height)
+const CLAMP_SIZE = 12; // small rounded square for routing clamps (v5 §11)
 
 const state = {
   /** @type {Project[]} */ projects: [],
@@ -55,8 +56,11 @@ const state = {
   /** @type {Cable[]} */ cables: [],
   /** @type {Bundle[]} */ bundles: [],
   /** @type {SetupTemplate[]} */ setupTemplates: [],
+  /** v5 — routing anchors. */
+  /** @type {Clamp[]} */ clamps: [],
+  /** @type {CableClamp[]} */ cableClamps: [],
   activeTypeId: /** @type {number|null} */ (null),
-  /** "frame" | "device" | "io" | "req" | "cable" | null */
+  /** "frame" | "device" | "io" | "req" | "cable" | "clamp" | null */
   tool: /** @type {string|null} */ (null),
   /** Canvas viewport — drives the SVG viewBox. */
   view: { x: 0, y: 0, zoom: 1 },
@@ -64,7 +68,7 @@ const state = {
   spaceHeld: false,
   /** Slice-7: when the user clicked a source port, this is its id. */
   cableDrawFromPortID: /** @type {number|null} */ (null),
-  /** @type {({kind: "frame"|"device"|"io"|"cable_type"|"requirement"|"cable"|"bundle"|"port", id: number} | {kind: "port_new", device_id: number}) | null} */ selection: null,
+  /** @type {({kind: "frame"|"device"|"io"|"cable_type"|"requirement"|"cable"|"bundle"|"port"|"clamp", id: number} | {kind: "port_new", device_id: number}) | null} */ selection: null,
 };
 
 // ---------- API client ---------- //
@@ -135,6 +139,15 @@ const listSetupTemplates = () => api("GET", `/setup-templates`);
 const applyTemplate = (pid, body) => api("POST", `/projects/${pid}/apply-template`, body);
 const syncExport     = (pid) => api("POST", `/projects/${pid}/sync/export`, {});
 
+// v5 — clamps + cable_clamps.
+const listClamps    = (pid) => api("GET", `/projects/${pid}/clamps`);
+const createClamp   = (pid, body) => api("POST", `/projects/${pid}/clamps`, body);
+const patchClamp    = (pid, id, body) => api("PATCH",  `/projects/${pid}/clamps/${id}`, body);
+const deleteClamp   = (pid, id) => api("DELETE", `/projects/${pid}/clamps/${id}`);
+const attachClampToCable = (pid, cid, body) => api("POST",   `/projects/${pid}/cables/${cid}/clamps`, body);
+const detachClampFromCable = (pid, cid, cmid) => api("DELETE", `/projects/${pid}/cables/${cid}/clamps/${cmid}`);
+const reorderCableClamps = (pid, cid, body) => api("PUT", `/projects/${pid}/cables/${cid}/clamps`, body);
+
 // ---------- DOM helpers ---------- //
 
 const $ = (sel) => /** @type {HTMLElement} */ (document.querySelector(sel));
@@ -258,6 +271,52 @@ function startPan(e) {
   svg.addEventListener("pointercancel", onUp);
 }
 
+// Left-click on empty canvas: ambiguous between "deselect" and "pan".
+// We resolve by movement — under the drag threshold m gets the historic
+// "click empties the selection" behaviour; past the threshold the gesture
+// promotes to a pan (Excalidraw / Figma standard). 3px screen-space dead
+// zone is enough that a steady click doesn't accidentally nudge the view.
+const EMPTY_CANVAS_PAN_THRESHOLD_PX = 3;
+
+function startEmptyCanvasGesture(e) {
+  const svg = /** @type {SVGSVGElement} */ ($("#canvas"));
+  const ctm = svg.getScreenCTM();
+  if (!ctm) return;
+  const scaleX = ctm.a, scaleY = ctm.d;
+  const startClientX = e.clientX, startClientY = e.clientY;
+  const startViewX = state.view.x, startViewY = state.view.y;
+  let panning = false;
+  try { svg.setPointerCapture(e.pointerId); } catch {}
+  const onMove = (ev) => {
+    const dx = ev.clientX - startClientX;
+    const dy = ev.clientY - startClientY;
+    if (!panning) {
+      if (Math.hypot(dx, dy) <= EMPTY_CANVAS_PAN_THRESHOLD_PX) return;
+      panning = true;
+      $(".canvas-wrap").classList.add("panning");
+    }
+    state.view.x = startViewX - dx / scaleX;
+    state.view.y = startViewY - dy / scaleY;
+    applyViewBox();
+  };
+  const onUp = (ev) => {
+    svg.removeEventListener("pointermove", onMove);
+    svg.removeEventListener("pointerup",   onUp);
+    svg.removeEventListener("pointercancel", onUp);
+    try { svg.releasePointerCapture(ev.pointerId); } catch {}
+    if (panning) {
+      $(".canvas-wrap").classList.remove("panning");
+      setViewInURL();
+    } else if (state.selection) {
+      state.selection = null;
+      render();
+    }
+  };
+  svg.addEventListener("pointermove", onMove);
+  svg.addEventListener("pointerup",   onUp);
+  svg.addEventListener("pointercancel", onUp);
+}
+
 function resetView() {
   state.view.zoom = 1;
   state.view.x = 0;
@@ -393,11 +452,17 @@ function renderCanvas() {
   const gFrames  = $("#canvas-frames");
   const gDevices = $("#canvas-devices");
   const gCables  = $("#canvas-cables");
+  const gBundles = $("#canvas-bundles");
+  const gClamps  = $("#canvas-clamps");
   const gIO      = $("#canvas-io");
+  const gDefs    = $("#canvas-defs");
   gFrames.innerHTML = "";
   gDevices.innerHTML = "";
   gCables.innerHTML = "";
+  gBundles.innerHTML = "";
+  gClamps.innerHTML = "";
   gIO.innerHTML = "";
+  gDefs.innerHTML = "";
 
   for (const f of state.frames) {
     const g = svgEl("g", { "data-frame-id": f.id });
@@ -415,8 +480,24 @@ function renderCanvas() {
     });
     label.textContent = f.name;
     g.append(rect, label);
+
+    // Bottom-right resize handle. Mirrors the device pattern — sits on
+    // top of the rect so its pointerdown wins, with stopPropagation in
+    // startFrameResize blocking the rect's startDrag underneath.
+    const FHSZ = 10;
+    const fHandle = svgEl("rect", {
+      x: f.x + f.width - FHSZ,
+      y: f.y + f.height - FHSZ,
+      width: FHSZ, height: FHSZ,
+      class: "frame-resize-handle",
+      "data-frame-id": f.id,
+    });
+    fHandle.addEventListener("pointerdown", (e) => startFrameResize(e, f.id));
+    g.append(fHandle);
+
     gFrames.append(g);
     rect.addEventListener("pointerdown", (e) => startDrag(e, "frame", f.id));
+    label.addEventListener("pointerdown", (e) => startDrag(e, "frame", f.id));
   }
 
   const portsByDevice = new Map();
@@ -539,30 +620,103 @@ function renderCanvas() {
     });
   }
 
-  // Cables — straight lines between resolved endpoint anchors.
-  // Auto-cables render with dashed stroke so m sees which the solver
-  // placed; manual cables are solid.
+  // Clamps — small grey rounded squares (per design v5 §11.9 q1).
+  // Slice 4 wires them into cable polylines; for slice 3 they just
+  // render + drag + select. Slice 5 adds a ×N count badge for clamps
+  // with ≥2 cables through them.
+  const cablesPerClamp = new Map();
+  for (const cc of state.cableClamps) {
+    cablesPerClamp.set(cc.clamp_id, (cablesPerClamp.get(cc.clamp_id) || 0) + 1);
+  }
+  for (const cl of state.clamps) {
+    const g = svgEl("g", { "data-clamp-id": cl.id });
+    const sz = CLAMP_SIZE;
+    const rect = svgEl("rect", {
+      x: cl.x - sz / 2, y: cl.y - sz / 2, width: sz, height: sz,
+      rx: 2, ry: 2,
+      class: "clamp" + (state.selection?.kind === "clamp" && state.selection.id === cl.id ? " selected" : "") + " svg-draggable",
+    });
+    g.append(rect);
+    const n = cablesPerClamp.get(cl.id) || 0;
+    if (n >= 2) {
+      const badge = svgEl("text", {
+        x: cl.x + sz / 2 + 2, y: cl.y - sz / 2 - 1,
+        class: "clamp-badge",
+      });
+      badge.textContent = `×${n}`;
+      g.append(badge);
+    }
+    if (cl.label) {
+      const label = svgEl("text", {
+        x: cl.x + sz / 2 + 4, y: cl.y + 3,
+        class: "clamp-label",
+      });
+      label.textContent = cl.label;
+      g.append(label);
+    }
+    gClamps.append(g);
+    rect.addEventListener("pointerdown", (e) => startDrag(e, "clamp", cl.id));
+  }
+
+  // Cables — polyline through endpoint(from) → clamps in ord sequence
+  // → endpoint(to). With zero clamps this collapses to a v0 straight
+  // line. Auto-cables render dashed; manual solid.
   const portByID = new Map(state.ports.map((p) => [p.id, p]));
   const deviceByID = new Map(state.devices.map((d) => [d.id, d]));
   const ioByID = new Map(state.ioMarkers.map((m) => [m.id, m]));
+  const clampByID = new Map(state.clamps.map((cl) => [cl.id, cl]));
+  // Pre-group cable_clamps by cable, sorted by ord.
+  const clampsByCable = new Map();
+  for (const cc of state.cableClamps) {
+    let arr = clampsByCable.get(cc.cable_id);
+    if (!arr) { arr = []; clampsByCable.set(cc.cable_id, arr); }
+    arr.push(cc);
+  }
+  for (const arr of clampsByCable.values()) arr.sort((a, b) => a.ord - b.ord);
+
+  // sharedSegments: segmentKey → { a, b, cables:[Cable] }. Built up
+  // during the per-cable loop, then walked in a second pass for the
+  // bundle overlay layer (v5 §11.3).
+  const sharedSegments = new Map();
+
   for (const c of state.cables) {
-    let fromAnchor = anchorForEndpoint(c.from_port_id, c.from_device_id, c.from_io_id, portByID, deviceByID, ioByID);
-    let toAnchor   = anchorForEndpoint(c.to_port_id,   c.to_device_id,   c.to_io_id,   portByID, deviceByID, ioByID);
-    if (!fromAnchor || !toAnchor) continue;
+    const built = cableVerticesWithKeys(c, portByID, deviceByID, ioByID, clampByID, clampsByCable);
+    if (!built) continue;
+    const { vertices, keys } = built;
+    // Bundle accumulator — record this cable on every segment of its
+    // resolved polyline keyed by an undirected pair of vertex IDs.
+    for (let i = 0; i < keys.length - 1; i++) {
+      const a = keys[i], b = keys[i + 1];
+      const segKey = a < b ? `${a}|${b}` : `${b}|${a}`;
+      let bucket = sharedSegments.get(segKey);
+      if (!bucket) {
+        bucket = { a: vertices[i], b: vertices[i + 1], cables: [] };
+        sharedSegments.set(segKey, bucket);
+      }
+      bucket.cables.push(c);
+    }
     // Replug preview: while m drags an endpoint handle, override the
     // affected end with the live cursor world position so the line
-    // tracks the pointer.
+    // tracks the pointer. Mid-vertices (clamps) are unchanged.
     if (cableReplug && cableReplug.cableID === c.id) {
-      if (cableReplug.end === "from") fromAnchor = { x: cableReplug.x, y: cableReplug.y };
-      else                            toAnchor   = { x: cableReplug.x, y: cableReplug.y };
+      const idx = cableReplug.end === "from" ? 0 : vertices.length - 1;
+      vertices[idx] = { x: cableReplug.x, y: cableReplug.y };
+    }
+    // Mid-segment drag preview: while m is bending a segment, insert
+    // a temp vertex at the cursor so the line tracks. On release this
+    // becomes a real clamp (or snaps to a nearby existing one).
+    if (cableMidDrag && cableMidDrag.cableID === c.id) {
+      const at = cableMidDrag.segmentIdx + 1;
+      vertices.splice(at, 0, { x: cableMidDrag.x, y: cableMidDrag.y });
     }
     const isSelected = state.selection?.kind === "cable" && state.selection.id === c.id;
     const color = cableTypeColor.get(c.type_id) || "#888";
-    const line = svgEl("line", {
-      x1: fromAnchor.x, y1: fromAnchor.y,
-      x2: toAnchor.x,   y2: toAnchor.y,
+    const pointsStr = vertices.map((v) => `${v.x},${v.y}`).join(" ");
+    const line = svgEl("polyline", {
+      points: pointsStr,
       class: "cable-line" + (c.auto ? " auto" : "") + (isSelected ? " selected" : ""),
       stroke: color,
+      fill: "none",
       "data-cable-id": c.id,
     });
     line.addEventListener("click", (e) => {
@@ -570,12 +724,20 @@ function renderCanvas() {
       state.selection = { kind: "cable", id: c.id };
       render();
     });
+    line.addEventListener("pointerdown", (e) => {
+      // Selected cable + non-endpoint click → start a mid-segment drag
+      // that inserts (or snaps to) a clamp on release. Bypasses the
+      // canvas-level handler so panning / device drag don't fire.
+      if (isSelected && e.button === 0 && !state.spaceHeld) {
+        startCableMidDrag(e, c, vertices);
+      }
+    });
     gCables.append(line);
-    // Endpoint handles — only on the currently-selected cable. Two small
-    // filled circles m can grab to drag the endpoint onto a new target.
+    // Endpoint handles — first + last vertex when selected.
     if (isSelected) {
-      for (const end of ["from", "to"]) {
-        const a = end === "from" ? fromAnchor : toAnchor;
+      const first = vertices[0];
+      const last  = vertices[vertices.length - 1];
+      for (const [end, a] of [["from", first], ["to", last]]) {
         const h = svgEl("circle", {
           cx: a.x, cy: a.y, r: 7,
           class: "cable-handle",
@@ -589,6 +751,97 @@ function renderCanvas() {
       }
     }
   }
+
+  // ---- bundle viz: shared segments + clamp count badges (v5 §11.3) ----
+  let gradSeq = 0;
+  for (const [segKey, bucket] of sharedSegments) {
+    if (bucket.cables.length < 2) continue;
+    // Distinct cable type IDs in this bundle, ordered by count desc
+    // (ties by id asc) per design v5 §11.9 q4.
+    const counts = new Map();
+    for (const c of bucket.cables) {
+      counts.set(c.type_id, (counts.get(c.type_id) || 0) + 1);
+    }
+    const distinctTypes = [...counts.entries()]
+      .sort((a, b) => b[1] - a[1] || a[0] - b[0])
+      .map(([id]) => id);
+    // Build a linearGradient perpendicular to the segment so the stripes
+    // run ACROSS the segment's thickness (visually: stripes parallel to
+    // the cable direction).
+    const { a, b } = bucket;
+    const dx = b.x - a.x, dy = b.y - a.y;
+    const len = Math.hypot(dx, dy) || 1;
+    // Perpendicular unit vector — gradient runs along this so the stops
+    // become bands along the segment's direction.
+    const px = -dy / len, py = dx / len;
+    const thickness = Math.min(12, 2 + bucket.cables.length);
+    const mx = (a.x + b.x) / 2, my = (a.y + b.y) / 2;
+    // Stops: hard-edged segments, one band per type.
+    const gradID = `bundle-grad-${gradSeq++}-${segKey.replace(/[^a-z0-9-]/gi, "_")}`;
+    const grad = svgEl("linearGradient", {
+      id: gradID,
+      gradientUnits: "userSpaceOnUse",
+      x1: mx + px * thickness / 2,
+      y1: my + py * thickness / 2,
+      x2: mx - px * thickness / 2,
+      y2: my - py * thickness / 2,
+    });
+    const n = distinctTypes.length;
+    for (let i = 0; i < n; i++) {
+      const color = cableTypeColor.get(distinctTypes[i]) || "#888";
+      const startStop = svgEl("stop", { offset: `${(i / n) * 100}%`, "stop-color": color });
+      const endStop   = svgEl("stop", { offset: `${((i + 1) / n) * 100}%`, "stop-color": color });
+      grad.append(startStop, endStop);
+    }
+    gDefs.append(grad);
+    // Tooltip listing the bundled cable types.
+    const titleText = distinctTypes
+      .map((id) => cableTypeColor.has(id) ? state.cableTypes.find((t) => t.id === id)?.name ?? `#${id}` : `#${id}`)
+      .join(" · ") + ` (${bucket.cables.length} cables)`;
+    const overlay = svgEl("line", {
+      x1: a.x, y1: a.y, x2: b.x, y2: b.y,
+      class: "bundle-line",
+      stroke: `url(#${gradID})`,
+      "stroke-width": thickness,
+    });
+    const title = svgEl("title", {});
+    title.textContent = titleText;
+    overlay.append(title);
+    gBundles.append(overlay);
+  }
+}
+
+
+// Compute the resolved polyline vertices for a cable plus a stable
+// vertex-key per vertex used to detect shared segments for bundle viz.
+// Vertex keys:
+//   - port:<id>    for a port-anchored endpoint
+//   - device:<id>  for a device-anchored endpoint (no port)
+//   - io:<id>      for an IO-anchored endpoint
+//   - clamp:<id>   for a mid-vertex
+// Returns null if either endpoint can't be resolved.
+function cableVerticesWithKeys(c, portByID, deviceByID, ioByID, clampByID, clampsByCable) {
+  const fromAnchor = anchorForEndpoint(c.from_port_id, c.from_device_id, c.from_io_id, portByID, deviceByID, ioByID);
+  const toAnchor   = anchorForEndpoint(c.to_port_id,   c.to_device_id,   c.to_io_id,   portByID, deviceByID, ioByID);
+  if (!fromAnchor || !toAnchor) return null;
+  function endpointKey(portID, deviceID, ioID) {
+    if (portID != null) return `port:${portID}`;
+    if (deviceID != null) return `device:${deviceID}`;
+    return `io:${ioID}`;
+  }
+  const vertices = [fromAnchor];
+  const keys = [endpointKey(c.from_port_id, c.from_device_id, c.from_io_id)];
+  const clamps = clampsByCable.get(c.id) || [];
+  for (const cc of clamps) {
+    const cl = clampByID.get(cc.clamp_id);
+    if (cl) {
+      vertices.push({ x: cl.x, y: cl.y });
+      keys.push(`clamp:${cl.id}`);
+    }
+  }
+  vertices.push(toAnchor);
+  keys.push(endpointKey(c.to_port_id, c.to_device_id, c.to_io_id));
+  return { vertices, keys };
 }
 
 /** Resolve a cable endpoint to {x, y} on the canvas. Returns null when
@@ -629,6 +882,7 @@ function renderInspector() {
     case "cable":       return renderInspectorCable(body, state.selection.id);
     case "port":        return renderInspectorPort(body, state.selection.id);
     case "port_new":    return renderInspectorPortNew(body, state.selection.device_id);
+    case "clamp":       return renderInspectorClamp(body, state.selection.id);
     default:            body.innerHTML = `<p class="muted">Nothing selected.</p>`;
   }
 }
@@ -1217,6 +1471,112 @@ function renderInspectorIO(body, id) {
   });
 }
 
+// Clamp inspector — label + position + cables-through list + delete.
+// Slice 4 wires the cables-through list to actual data; for slice 3 it
+// reads whatever's already on state.cableClamps (initially empty for a
+// freshly-placed clamp).
+function renderInspectorClamp(body, id) {
+  const cl = state.clamps.find((x) => x.id === id);
+  if (!cl) { body.innerHTML = ""; return; }
+  const frame = cl.frame_id ? state.frames.find((f) => f.id === cl.frame_id) : null;
+  const cableTypeColor = new Map(state.cableTypes.map((t) => [t.id, t.color]));
+  const deviceByID = new Map(state.devices.map((d) => [d.id, d]));
+  const portByID = new Map(state.ports.map((p) => [p.id, p]));
+  const ioByID = new Map(state.ioMarkers.map((m) => [m.id, m]));
+  const cablesThrough = state.cableClamps
+    .filter((cc) => cc.clamp_id === id)
+    .map((cc) => state.cables.find((c) => c.id === cc.cable_id))
+    .filter(Boolean);
+  function endpointLabel(c, end) {
+    const portID = end === "from" ? c.from_port_id : c.to_port_id;
+    const devID  = end === "from" ? c.from_device_id : c.to_device_id;
+    const ioID   = end === "from" ? c.from_io_id : c.to_io_id;
+    if (portID != null) {
+      const p = portByID.get(portID);
+      const d = p && deviceByID.get(p.device_id);
+      return `${d?.name ?? "?"} · ${p?.label ?? "port"}`;
+    }
+    if (devID != null) return deviceByID.get(devID)?.name ?? "(missing device)";
+    if (ioID  != null) return ioByID.get(ioID)?.label ?? "(missing IO)";
+    return "?";
+  }
+  const cablesHtml = cablesThrough.length
+    ? cablesThrough.map((c) => `
+        <div class="port-row" data-cable-id="${c.id}">
+          <span class="swatch" style="background:${cableTypeColor.get(c.type_id) || "#888"}"></span>
+          <span class="label">${escapeHtml(endpointLabel(c, "from"))} ↔ ${escapeHtml(endpointLabel(c, "to"))}</span>
+          <span class="conn">
+            <button type="button" class="btn-link clamp-detach" data-cable-id="${c.id}" title="Remove this clamp from the cable">×</button>
+          </span>
+        </div>`).join("")
+    : `<p class="muted" style="font-size:12px">Not on any cable yet.</p>`;
+
+  body.innerHTML = `
+    <p class="section-title">Clamp</p>
+    <label class="field">
+      <span>Label</span>
+      <input class="inline-input" id="clamp-label" value="" />
+    </label>
+    <dl>
+      <dt>x</dt><dd id="clamp-x"></dd>
+      <dt>y</dt><dd id="clamp-y"></dd>
+      <dt>frame</dt><dd id="clamp-frame"></dd>
+    </dl>
+    <p class="section-title">Cables through</p>
+    ${cablesHtml}
+    <div class="inspector-actions">
+      <button type="button" class="btn btn-danger btn-tiny" id="clamp-delete">Delete clamp</button>
+    </div>
+  `;
+  body.querySelector("#clamp-label").value = cl.label;
+  body.querySelector("#clamp-x").textContent = cl.x.toFixed(0);
+  body.querySelector("#clamp-y").textContent = cl.y.toFixed(0);
+  body.querySelector("#clamp-frame").textContent = frame ? frame.name : "—";
+
+  bindDebouncedRename(body.querySelector("#clamp-label"), async (label) => {
+    if (!state.active) return;
+    const updated = await patchClamp(state.active.id, cl.id, { label });
+    Object.assign(cl, updated);
+    renderCanvas();
+  });
+
+  // Per-cable detach in the cables-through list.
+  body.querySelectorAll(".clamp-detach").forEach((btn) => {
+    btn.addEventListener("click", async (e) => {
+      e.stopPropagation();
+      if (!state.active) return;
+      const cableID = Number(btn.getAttribute("data-cable-id"));
+      try {
+        await detachClampFromCable(state.active.id, cableID, cl.id);
+        // Re-fetch snapshot fragment to keep ord contiguous.
+        const snap = await getSnapshot(state.active.id);
+        state.cableClamps = snap.cable_clamps || [];
+        render();
+      } catch (ex) {
+        alert(`Detach failed: ${ex.message}`);
+      }
+    });
+  });
+
+  body.querySelector("#clamp-delete").addEventListener("click", async () => {
+    if (!state.active) return;
+    const n = cablesThrough.length;
+    const prompt = n > 0
+      ? `This clamp is on ${n} cable(s). Delete it and remove from all of them?`
+      : "Delete this clamp?";
+    if (!confirm(prompt)) return;
+    try {
+      await deleteClamp(state.active.id, cl.id);
+      state.clamps = state.clamps.filter((c) => c.id !== id);
+      state.cableClamps = state.cableClamps.filter((cc) => cc.clamp_id !== id);
+      state.selection = null;
+      render();
+    } catch (ex) {
+      alert(`Delete failed: ${ex.message}`);
+    }
+  });
+}
+
 // Port editor — type / edge / label / delete. m can also navigate back
 // to the device by clicking "back to device" or anywhere on the device.
 function renderInspectorPort(body, id) {
@@ -1568,6 +1928,8 @@ async function activateProject(id) {
     state.requirements = [];
     state.cables = [];
     state.bundles = [];
+    state.clamps = [];
+    state.cableClamps = [];
     state.selection = null;
     setActiveInURL(null);
     render();
@@ -1584,6 +1946,8 @@ async function activateProject(id) {
     state.bundles = snap.bundles || [];
     state.requirements = snap.connection_requirements || [];
     state.cableTypes = snap.cable_types || [];
+    state.clamps = snap.clamps || [];
+    state.cableClamps = snap.cable_clamps || [];
     state.selection = null;
     setActiveInURL(id);
     // Hydrate the device-type catalog for this project — used by the
@@ -1607,6 +1971,8 @@ async function activateProject(id) {
       state.requirements = [];
       state.cables = [];
       state.bundles = [];
+      state.clamps = [];
+      state.cableClamps = [];
       setActiveInURL(null);
       render();
     } else {
@@ -1624,6 +1990,7 @@ function armTool(tool) {
   wrap.classList.toggle("tool-frame",  tool === "frame");
   wrap.classList.toggle("tool-device", tool === "device");
   wrap.classList.toggle("tool-cable",  tool === "cable");
+  wrap.classList.toggle("tool-clamp",  tool === "clamp");
   for (const btn of document.querySelectorAll("[data-tool]")) {
     btn.classList.toggle("armed", btn.getAttribute("data-tool") === tool);
   }
@@ -1655,6 +2022,7 @@ function bindTools() {
     else if (e.key === "f" || e.key === "F") armTool("frame");
     else if (e.key === "d" || e.key === "D") armTool("device");
     else if (e.key === "i" || e.key === "I") armTool("io");
+    else if (e.key === "c" || e.key === "C") armTool("clamp");
     else if (e.key === "r" || e.key === "R") armTool("req");
     else if (e.key === "s" || e.key === "S") openSolveModal();
   });
@@ -1679,6 +2047,11 @@ let rubberStart = /** @type {{x:number,y:number}|null} */ (null);
 // on a .cable-handle, used by renderCanvas to anchor the dragged end
 // at the cursor; cleared on pointerup (commit or cancel).
 let cableReplug = /** @type {{cableID: number, end: "from"|"to", x: number, y: number}|null} */ (null);
+// Mid-segment drag — m grabs a point on a cable's polyline (not on an
+// endpoint handle, not on an existing clamp vertex) and drags. On
+// release, either snap to a nearby clamp or create a fresh one at the
+// drop point and insert at the right `ord`.
+let cableMidDrag = /** @type {{cableID: number, segmentIdx: number, x: number, y: number}|null} */ (null);
 
 function onCanvasPointerDown(e) {
   // Pan gestures win over every tool. Middle-click and Space+drag both
@@ -1714,18 +2087,29 @@ function onCanvasPointerDown(e) {
     placeDeviceAt(p);
     return;
   }
+  if (state.tool === "clamp") {
+    e.preventDefault();
+    placeClampAt(p, e);
+    return;
+  }
   if (state.tool === "io") {
     e.preventDefault();
     placeIOMarkerAt(p);
     return;
   }
 
-  // No tool armed: clicks that started on a device/frame/io go to their
-  // own handlers (drag / select). Leave them alone.
-  if (e.target instanceof Element && e.target.closest("[data-device-id], [data-frame-id], [data-io-id]")) return;
+  // No tool armed: clicks that started on a device/frame/io/clamp/port/cable
+  // go to their own handlers (drag / select / replug). Leave them alone.
+  if (e.target instanceof Element && e.target.closest("[data-device-id], [data-frame-id], [data-io-id], [data-clamp-id], [data-port-id], [data-cable-id]")) return;
 
-  // Plain canvas click = clear selection.
-  if (state.selection) { state.selection = null; render(); }
+  // Empty-canvas left-click without an active cable draw: start a
+  // maybe-pan gesture. It promotes to a pan once the cursor crosses the
+  // drag threshold; if m clicks without dragging it falls back to the
+  // historic "clear selection" UX. Other buttons fall through (middle is
+  // already handled above, right-click is the browser context menu).
+  if (e.button === 0 && state.cableDrawFromPortID == null) {
+    startEmptyCanvasGesture(e);
+  }
 }
 
 function startFrameRubberBand(e, p0) {
@@ -2016,6 +2400,51 @@ function startResize(e, deviceID) {
   svg.addEventListener("pointercancel", onUp);
 }
 
+// Frame bottom-right resize gesture. Mirrors startResize for devices,
+// but PATCHes /frames/:id and uses a larger minimum (frames host
+// devices + IO markers + clamps, so 200×150 is the smallest useful
+// canvas). Contained children stay at their absolute positions — the
+// frame body drag is what moves them; resize only changes the frame's
+// own bounds.
+function startFrameResize(e, frameID) {
+  if (!state.active) return;
+  // Hard-stop so the rect's pointerdown doesn't also fire startDrag.
+  e.stopPropagation();
+  e.preventDefault();
+  const f = state.frames.find((x) => x.id === frameID);
+  if (!f) return;
+  const startWidth = f.width, startHeight = f.height;
+  const startWorld = svgPoint(e);
+  const svg = /** @type {SVGSVGElement} */ ($("#canvas"));
+  try { svg.setPointerCapture(e.pointerId); } catch {}
+  const MIN_FRAME_W = 200, MIN_FRAME_H = 150;
+  const onMove = (ev) => {
+    const p = svgPoint(ev);
+    f.width  = Math.max(MIN_FRAME_W, startWidth  + (p.x - startWorld.x));
+    f.height = Math.max(MIN_FRAME_H, startHeight + (p.y - startWorld.y));
+    renderCanvas();
+  };
+  const onUp = async (ev) => {
+    svg.removeEventListener("pointermove", onMove);
+    svg.removeEventListener("pointerup",   onUp);
+    svg.removeEventListener("pointercancel", onUp);
+    try { svg.releasePointerCapture(ev.pointerId); } catch {}
+    if (f.width === startWidth && f.height === startHeight) return;
+    try {
+      const updated = await patchFrame(state.active.id, f.id, {
+        width: f.width, height: f.height,
+      });
+      Object.assign(f, updated);
+      renderCanvas();
+    } catch (err) {
+      alert(`Resize failed: ${err.message}`);
+    }
+  };
+  svg.addEventListener("pointermove", onMove);
+  svg.addEventListener("pointerup",   onUp);
+  svg.addEventListener("pointercancel", onUp);
+}
+
 // Find the topmost canvas element under (clientX, clientY) that maps to
 // a cable endpoint target. Returns { kind, id } for port / device / IO,
 // or null when m dropped on empty canvas.
@@ -2105,6 +2534,121 @@ function startCableReplug(e, cableID, end) {
   svg.addEventListener("pointercancel", onUp);
 }
 
+// Mid-segment cable drag: m grabs a point on a selected cable's
+// polyline (not on an endpoint handle) and drags. On release, snap to
+// the nearest clamp within MID_SNAP world-units, or create a fresh one
+// at the drop point. Either way, attach it to the cable at the right
+// ord so the new vertex sits inside the segment m was bending.
+const MID_SNAP_PX = 16; // visual constant — divided by current zoom
+function startCableMidDrag(e, cable, vertices) {
+  if (!state.active) return;
+  // Refuse if the click target is an endpoint handle — let the replug
+  // handler own that gesture.
+  if (e.target instanceof Element && e.target.classList.contains("cable-handle")) return;
+  e.stopPropagation();
+  e.preventDefault();
+  const svg = /** @type {SVGSVGElement} */ ($("#canvas"));
+  const start = svgPoint(e);
+  // Identify which segment the click landed closest to.
+  const segIdx = nearestSegmentIndex(vertices, start);
+  try { svg.setPointerCapture(e.pointerId); } catch {}
+  $(".canvas-wrap").classList.add("replugging");
+  cableMidDrag = { cableID: cable.id, segmentIdx: segIdx, x: start.x, y: start.y };
+  renderCanvas();
+
+  const onMove = (ev) => {
+    const p = svgPoint(ev);
+    cableMidDrag = { cableID: cable.id, segmentIdx: segIdx, x: p.x, y: p.y };
+    renderCanvas();
+  };
+  const onUp = async (ev) => {
+    svg.removeEventListener("pointermove", onMove);
+    svg.removeEventListener("pointerup",   onUp);
+    svg.removeEventListener("pointercancel", onUp);
+    try { svg.releasePointerCapture(ev.pointerId); } catch {}
+    $(".canvas-wrap").classList.remove("replugging");
+    const dropWorld = svgPoint(ev);
+    cableMidDrag = null;
+    // Cancel if the cursor barely moved (≤ a few px in world coords) —
+    // m probably clicked the cable to select it, not bend it.
+    if (Math.hypot(dropWorld.x - start.x, dropWorld.y - start.y) < 4) {
+      renderCanvas();
+      return;
+    }
+    // Snap radius in world coords — visual constant per design v5 §11.9 q2.
+    const snapRadius = MID_SNAP_PX / state.view.zoom;
+    let nearest = null;
+    let bestDist = Infinity;
+    for (const cl of state.clamps) {
+      const d = Math.hypot(cl.x - dropWorld.x, cl.y - dropWorld.y);
+      if (d < bestDist) { bestDist = d; nearest = cl; }
+    }
+    try {
+      let clampID;
+      if (nearest && bestDist <= snapRadius) {
+        // Snap onto existing clamp — but only if it's not already on
+        // this cable (UNIQUE constraint would 409). Skip silently in
+        // that case rather than spamming an alert.
+        const already = state.cableClamps.some(
+          (cc) => cc.cable_id === cable.id && cc.clamp_id === nearest.id,
+        );
+        if (already) { renderCanvas(); return; }
+        clampID = nearest.id;
+      } else {
+        // Fresh clamp at the drop point.
+        const frame = frameAt(dropWorld.x, dropWorld.y);
+        const newClamp = await createClamp(state.active.id, {
+          x: dropWorld.x, y: dropWorld.y,
+          frame_id: frame ? frame.id : undefined,
+        });
+        state.clamps.push(newClamp);
+        clampID = newClamp.id;
+      }
+      // Insert at ord = segIdx + 1 (1-based; segmentIdx is the segment
+      // between vertices[segIdx] and vertices[segIdx + 1]).
+      const cc = await attachClampToCable(state.active.id, cable.id, {
+        clamp_id: clampID, ord: segIdx + 1,
+      });
+      // Refresh cable_clamps so the new ord + any shifted neighbours
+      // are reflected without a full snapshot reload.
+      const snap = await getSnapshot(state.active.id);
+      state.cableClamps = snap.cable_clamps || [];
+      render();
+      // Silence unused-var lint without dropping the result.
+      void cc;
+    } catch (err) {
+      alert(`Insert clamp failed: ${err.message}`);
+      renderCanvas();
+    }
+  };
+  svg.addEventListener("pointermove", onMove);
+  svg.addEventListener("pointerup",   onUp);
+  svg.addEventListener("pointercancel", onUp);
+}
+
+// Index of the segment in `vertices` closest to point p. Segment i sits
+// between vertices[i] and vertices[i+1].
+function nearestSegmentIndex(vertices, p) {
+  let best = 0;
+  let bestDist = Infinity;
+  for (let i = 0; i < vertices.length - 1; i++) {
+    const a = vertices[i], b = vertices[i + 1];
+    const d = pointSegmentDistance(p, a, b);
+    if (d < bestDist) { bestDist = d; best = i; }
+  }
+  return best;
+}
+
+// Shortest distance from point p to the line segment a–b.
+function pointSegmentDistance(p, a, b) {
+  const dx = b.x - a.x, dy = b.y - a.y;
+  const lenSq = dx * dx + dy * dy;
+  if (lenSq === 0) return Math.hypot(p.x - a.x, p.y - a.y);
+  let t = ((p.x - a.x) * dx + (p.y - a.y) * dy) / lenSq;
+  t = Math.max(0, Math.min(1, t));
+  return Math.hypot(p.x - (a.x + t * dx), p.y - (a.y + t * dy));
+}
+
 /** Port-click flow:
  *  - A cable draw is in progress (cableDrawFromPortID set):
  *     same port → cancel; another port → finish the cable.
@@ -2239,6 +2783,40 @@ async function createPortFromForm(deviceID, typeID, edge, label) {
   }
 }
 
+// + Clamp tool: drop a standalone routing anchor at the click. If the
+// click landed on a cable (slice 4 will detect this), the clamp will
+// also be attached to that cable mid-segment. For slice 3 we just
+// place it.
+async function placeClampAt(p, e) {
+  if (!state.active) return;
+  armTool(null);
+  // Did the click hit a cable? If so, attach the new clamp to that cable.
+  const cableEl = e && e.target instanceof Element
+    ? e.target.closest("[data-cable-id]")
+    : null;
+  const cableID = cableEl ? Number(cableEl.getAttribute("data-cable-id")) : null;
+  const frame = frameAt(p.x, p.y);
+  try {
+    const c = await createClamp(state.active.id, {
+      x: p.x, y: p.y,
+      frame_id: frame ? frame.id : undefined,
+    });
+    state.clamps.push(c);
+    if (cableID) {
+      try {
+        const cc = await attachClampToCable(state.active.id, cableID, { clamp_id: c.id });
+        state.cableClamps.push(cc);
+      } catch (ex) {
+        alert(`Attach to cable failed: ${ex.message}`);
+      }
+    }
+    state.selection = { kind: "clamp", id: c.id };
+    render();
+  } catch (err) {
+    alert(`Create clamp failed: ${err.message}`);
+  }
+}
+
 async function placeIOMarkerAt(p) {
   if (!state.active) return;
   armTool(null);
@@ -2329,19 +2907,21 @@ function startDrag(e, kind, id) {
 
   const svg = /** @type {SVGSVGElement} */ ($("#canvas"));
   const start = svgPoint(e);
-  /** @type {Frame|Device|IOMarker|undefined} */
+  /** @type {Frame|Device|IOMarker|Clamp|undefined} */
   let obj;
   if (kind === "frame")       obj = state.frames.find((f) => f.id === id);
   else if (kind === "device") obj = state.devices.find((d) => d.id === id);
   else if (kind === "io")     obj = state.ioMarkers.find((m) => m.id === id);
+  else if (kind === "clamp")  obj = state.clamps.find((c) => c.id === id);
   if (!obj) return;
   const startX = obj.x;
   const startY = obj.y;
 
-  // For frame drags, remember the contained devices + IO markers + their
-  // offsets so they follow the frame visually + persist on release.
+  // For frame drags, remember the contained devices + IO markers + clamps
+  // + their offsets so they follow the frame visually + persist on release.
   let trackedDevices = /** @type {{d: Device, sx: number, sy: number}[]} */ ([]);
   let trackedIOs     = /** @type {{m: IOMarker, sx: number, sy: number}[]} */ ([]);
+  let trackedClamps  = /** @type {{c: Clamp, sx: number, sy: number}[]} */ ([]);
   if (kind === "frame") {
     for (const d of state.devices) {
       if (d.frame_id === obj.id) {
@@ -2353,6 +2933,11 @@ function startDrag(e, kind, id) {
         trackedIOs.push({ m, sx: m.x, sy: m.y });
       }
     }
+    for (const c of state.clamps) {
+      if (c.frame_id === obj.id) {
+        trackedClamps.push({ c, sx: c.x, sy: c.y });
+      }
+    }
   }
 
   // Capture the rect element NOW: by the time onUp fires async, the
@@ -2376,6 +2961,7 @@ function startDrag(e, kind, id) {
     if (kind === "frame") {
       for (const t of trackedDevices) { t.d.x = t.sx + dx; t.d.y = t.sy + dy; }
       for (const t of trackedIOs)     { t.m.x = t.sx + dx; t.m.y = t.sy + dy; }
+      for (const t of trackedClamps)  { t.c.x = t.sx + dx; t.c.y = t.sy + dy; }
     }
     renderCanvas();
   };
@@ -2392,12 +2978,14 @@ function startDrag(e, kind, id) {
       if (kind === "frame") {
         const f = /** @type {Frame} */ (obj);
         await patchFrame(state.active.id, f.id, { x: f.x, y: f.y });
-        // Persist contained devices + IO markers too.
+        // Persist contained devices + IO markers + clamps too.
         await Promise.all([
           ...trackedDevices.map((t) =>
             patchDevice(state.active.id, t.d.id, { x: t.d.x, y: t.d.y })),
           ...trackedIOs.map((t) =>
             patchIOMarker(state.active.id, t.m.id, { x: t.m.x, y: t.m.y })),
+          ...trackedClamps.map((t) =>
+            patchClamp(state.active.id, t.c.id, { x: t.c.x, y: t.c.y })),
         ]);
       } else if (kind === "device") {
         const d = /** @type {Device} */ (obj);
@@ -2412,7 +3000,7 @@ function startDrag(e, kind, id) {
           d.frame_id = newFrameID;
         }
         await patchDevice(state.active.id, d.id, patchBody);
-      } else /* io */ {
+      } else if (kind === "io") {
         const m = /** @type {IOMarker} */ (obj);
         const cx = m.x + IO_SIZE / 2;
         const cy = m.y + IO_SIZE / 2;
@@ -2424,6 +3012,16 @@ function startDrag(e, kind, id) {
           m.frame_id = newFrameID;
         }
         await patchIOMarker(state.active.id, m.id, patchBody);
+      } else /* clamp */ {
+        const c = /** @type {Clamp} */ (obj);
+        const targetFrame = frameAt(c.x, c.y);
+        const newFrameID = targetFrame ? targetFrame.id : null;
+        const patchBody = { x: c.x, y: c.y };
+        if ((c.frame_id ?? null) !== newFrameID) {
+          patchBody.frame_id = newFrameID;
+          c.frame_id = newFrameID;
+        }
+        await patchClamp(state.active.id, c.id, patchBody);
       }
     } catch (err) {
       alert(`Save failed: ${err.message}`);
@@ -3224,7 +3822,6 @@ async function boot() {
   bindCloseButtons($("#modal-admin"));
 
   $("#btn-new-project").addEventListener("click", openNewProjectModal);
-  $("#btn-add-type").addEventListener("click", () => openCableTypeModal(null));
   $("#btn-delete-project").addEventListener("click", openDeleteProjectModal);
   $("#btn-admin").addEventListener("click", openAdminModal);
   $("#btn-solve").addEventListener("click", openSolveModal);

web/static/style.css

@@ -180,7 +180,20 @@ body {
   fill: var(--accent);
   font-size: 13px;
   font-weight: 600;
-  pointer-events: none;
+  cursor: grab;
+}
+
+/* Frame bottom-right resize affordance. Mirrors .device-resize-handle
+   but uses the accent-on-frame palette so it reads as part of the frame
+   chrome rather than the device. */
+.frame-resize-handle {
+  fill: rgba(0, 0, 0, 0.15);
+  stroke: rgba(0, 0, 0, 0.25);
+  stroke-width: 1;
+  cursor: nwse-resize;
+}
+.frame-resize-handle:hover {
+  fill: rgba(0, 0, 0, 0.3);
 }
 
 /* Stroke + fill come from the device's user-set colour, written as
@@ -227,9 +240,44 @@ body {
 .canvas-wrap.tool-device #canvas *,
 .canvas-wrap.tool-io     #canvas,
 .canvas-wrap.tool-io     #canvas *,
+.canvas-wrap.tool-clamp  #canvas,
+.canvas-wrap.tool-clamp  #canvas *,
 .canvas-wrap.tool-cable  #canvas,
 .canvas-wrap.tool-cable  #canvas * { cursor: crosshair !important; }
 
+/* Clamps — small grey rounded squares (v5 §11). Cables route through
+   them in `ord` sequence. */
+.clamp {
+  fill: rgba(120, 120, 120, 0.85);
+  stroke: rgba(40, 40, 40, 0.85);
+  stroke-width: 1.5;
+  cursor: grab;
+}
+.clamp.selected {
+  stroke-width: 3;
+  filter: drop-shadow(0 0 4px var(--accent));
+}
+.clamp-label {
+  fill: var(--text-muted);
+  font-size: 10px;
+  pointer-events: none;
+}
+/* Shared-segment count badge — m sees ×N next to clamps that route
+   ≥ 2 cables. */
+.clamp-badge {
+  fill: var(--text);
+  font-size: 10px;
+  font-weight: 700;
+  pointer-events: none;
+}
+/* Bundle overlay — thick striped polyline drawn on top of individual
+   cables along shared segments. v5 §11.3. */
+.bundle-line {
+  fill: none;
+  pointer-events: none;
+  opacity: 0.85;
+}
+
 .btn-link {
   background: transparent;
   border: 0;

web/web.go

@@ -1,5 +1,5 @@
 // Package web bundles the frontend (HTML/JS/CSS) into the Go binary
-// via embed.FS so deploying mCables means shipping one file.
+// via embed.FS so deploying CableGUI means shipping one file.
 package web
 
 import (