fix(t-paliad-111): bug bundle (correctness) — UPC GESAMTKOSTEN, court-set dates, REGEL save flow

Three correctness bugs from the t-paliad-101 QA sweep, fixed together since
they all change displayed/saved numbers users rely on.

B1 — Kostenrechner UPC GESAMTKOSTEN double-count
  ComputeUPCInstance was setting InstanceTotal = effectiveCourtFee +
  recoverableCeiling. The R.152 recoverable-cost cap is the OPPOSING
  side's worst-case loss-of-suit liability, not the user's own cost —
  folding it into GESAMTKOSTEN inflated the UPC total under a label
  that means "your outlay," and the DE LG/OLG/BGH branches don't add
  any opponent estimate. Drop it from InstanceTotal; the ceiling
  still surfaces as its own RecoverableCeiling line item.

  Live pre-fix on paliad.de (Streitwert 100k, UPC 1. Instanz only):
    instanceTotal = 52600 = 14600 court fee + 38000 R.152 ceiling
  Post-fix:
    instanceTotal = 14600 (court fee only); RecoverableCeiling stays 38000

B3 — Court-determined Termine emit trigger date as a real-looking date
  Zwischenverfahren / Mündliche Verhandlung / Entscheidung all live in
  paliad.deadline_rules with duration_value=0 and parent_id=NULL, so
  Calculate() classified them as IsRootEvent and emitted the trigger
  date as their own DueDate. Worse, RoP.151 "Antrag auf Kostenentscheidung"
  parents off inf.decision and chained 1 month off the placeholder ->
  bogus deadline that the UI rendered as real.

  Fix: classify a zero-duration rule as IsCourtSet (not IsRootEvent)
  when primary_party = 'court' or event_type ∈ {hearing, decision,
  order}. Track court-set rule IDs and propagate IsCourtSet downstream
  to any rule whose parent is court-set, so RoP.151 also surfaces as
  court-set rather than a fabricated date. Save-modal already greys
  out IsCourtSet rows so the "Gerichtsbestimmte Termine ohne Datum
  werden übersprungen" footnote becomes truthful again.

  Live pre-fix on paliad.de (UPC_INF, trigger 2026-04-29):
    Zwischenverfahren / Oral / Entscheidung -> dueDate 2026-04-29
    Antrag auf Kostenentscheidung -> 2026-05-29 (bogus, +1mo from trigger)

B6 — Fristenrechner save flow stored rule code in TITLE
  Frontend was concatenating "RoP.023 — Klageerwiderung" into the
  title because deadlines had nowhere else to put the citation, and
  the /deadlines REGEL column ended up showing "—". Add migration 032
  with a paliad.deadlines.rule_code text column, plumb it through
  CreateDeadlineInput / insertTx, drop the now-redundant r.code AS
  rule_code JOIN alias on the list query (the deadline owns its
  citation), and render f.rule_code on the project-detail deadlines
  table + /deadlines events list + deadline-detail page.

Build, vet, and tests all clean. New unit test
TestIsCourtDeterminedRule pins the B3 discriminator across the
event_type / primary_party combinations seen in migrations 012 + 031.

Repro creds: tester@hlc.de

frontend/src/client/deadlines-detail.ts

@@ -18,6 +18,7 @@ interface Deadline {
   status: string;
   source: string;
   rule_id?: string;
+  rule_code?: string;
   notes?: string;
   created_at: string;
   completed_at?: string;
@@ -170,6 +171,10 @@ function render() {
   if (rule) {
     const code = rule.rule_code || rule.code || "";
     ruleEl.textContent = code ? `${code} — ${rule.name}` : rule.name;
+  } else if (deadline.rule_code) {
+    // Fristenrechner-saved deadlines carry rule_code directly without
+    // a rule_id (no rule UUID round-trips through the public API).
+    ruleEl.textContent = deadline.rule_code;
   } else {
     ruleEl.textContent = "—";
   }

frontend/src/client/events.ts

@@ -201,6 +201,10 @@ function urgencyClass(item: EventListItem): string {
 
 function ruleDisplay(item: EventListItem): string {
   if (item.type !== "deadline") return "";
+  // Prefer the saved citation (RoP.023, R.151) over the rule name —
+  // REGEL is meant for the legal reference, not the rule's display
+  // name (which is the title column's job).
+  if (item.rule_code && item.rule_code.trim()) return esc(item.rule_code);
   const lang = getLang();
   const localized = lang === "en" ? item.rule_name_en : item.rule_name;
   if (localized && localized.trim()) return esc(localized);
@@ -391,7 +395,7 @@ function render() {
   const anyEventType = allItems.some((x) => (x.event_type_ids ?? []).length > 0);
   const anyLocation = allItems.some((x) => !!x.location);
   const anyAppointmentType = allItems.some((x) => !!x.appointment_type);
-  const anyRule = allItems.some((x) => x.type === "deadline" && (x.rule_name || x.rule_name_en));
+  const anyRule = allItems.some((x) => x.type === "deadline" && (x.rule_code || x.rule_name || x.rule_name_en));
   const anyStatus = anyDeadline; // appointments don't carry a status column
 
   table?.classList.toggle("events-table--hide-row-type", !anyDeadline || !anyAppointment);

frontend/src/client/fristenrechner.ts

@@ -247,7 +247,8 @@ async function submitSave() {
     if (!dl || !dl.dueDate) return;
     const dlName = getLang() === "en" ? dl.nameEN : dl.name;
     deadlinesPayload.push({
-      title: dl.ruleRef ? `${dl.ruleRef} \u2014 ${dlName}` : dlName,
+      title: dlName,
+      rule_code: dl.ruleRef || undefined,
       due_date: dl.dueDate,
       original_due_date: dl.originalDate || undefined,
       source: "fristenrechner",

frontend/src/client/projects-detail.ts

@@ -80,6 +80,7 @@ interface Deadline {
   due_date: string;
   status: string;
   rule_id?: string;
+  rule_code?: string;
 }
 
 interface Appointment {
@@ -443,7 +444,7 @@ function renderDeadlines() {
         </td>
         <td class="frist-col-due ${urgency}"><span class="frist-due-dot"></span>${fmtDateOnly(f.due_date)}</td>
         <td class="frist-col-title ${titleClass}">${esc(f.title)}</td>
-        <td class="frist-col-rule">—</td>
+        <td class="frist-col-rule">${f.rule_code ? esc(f.rule_code) : "—"}</td>
         <td><span class="entity-status-chip entity-status-${esc(f.status)}">${esc(statusLabel)}</span></td>
       </tr>`;
     })