feat(db): mig 152 — dedupe identical sequencing_rule clones (5 archived) (t-paliad-321 / m/paliad#144 follow-up)

Mig 151 (t-paliad-319) archived 5 of 6 duplicate procedural_events for
"Mängelbeseitigung / Zahlung" and reparented their sequencing_rules
onto the canonical PE. The 6 sequencing_rules themselves were left
active — and they are byte-for-byte clones (proceeding_type_id=NULL,
rule_code=NULL, duration 14d, primary_party=NULL, condition_expr=NULL,
…). The admin shows six indistinguishable rows for one legal concept.

This migration archives 5 of 6, keeping the row with the
lexicographically lowest UUID as canonical.

Pre-write verification (Supabase MCP, 2026-05-26):
- Exactly 1 clone-group surfaces under the full-signature query
  (procedural_event_id, proceeding_type_id, rule_code, duration_*,
  primary_party, condition_expr::text, trigger_event_id, alt_*,
  anchor_alt, combine_op, parent_id, is_spawn, spawn_*):
  6 "Mängelbeseitigung / Zahlung" rows.
- 0 paliad.deadlines reference any of the 5 to-be-archived rows
  (verified via deadlines.sequencing_rule_id JOIN; rule_id column
  was dropped in mig 140 / Slice B.4).
- Other name-duplicates (Antrag auf Patentänderung×4, Beginn des
  Hauptsacheverfahrens×2, Berufungsbegründung-R.220.1×2,
  Berufungsschrift-R.220.1×2) do NOT collapse under this signature —
  their proceeding_type_id / rule_code / duration / primary_party
  differ. Legitimately distinct rules per proceeding. This mig
  leaves them alone.

Migration shape (mirrors mig 151):
1. Build dedupe mapping (duplicate_id → canonical_id) into a
   ROW_NUMBER() OVER (PARTITION BY full-signature ORDER BY
   created_at, id::text) TEMP table.
2. PRE NOTICE: surface every clone-group with its canonical + dups
   so the deploy log shows what's about to be touched (m may want
   to spot-check).
3. Snapshot the duplicates into paliad.sequencing_rules_pre_152
   (precedent pre_091/093/095/098/140/151).
4. Reparent paliad.deadlines.sequencing_rule_id duplicate → canonical
   BEFORE archiving (defensive no-op today).
5. set_config('paliad.audit_reason', …) — defensive; sequencing_rules
   has no audit trigger yet (mig 151 §scope verified), but a future
   trigger would inherit the reason automatically.
6. UPDATE sequencing_rules SET is_active=false,
   lifecycle_state='archived' WHERE id IN dups.
7. POST assertions: expected archive count met, zero clone groups
   remaining in active+published, zero live deadlines pointing at
   an archived sequencing_rule. RAISE EXCEPTION on any mismatch.

Down: best-effort revert (flips archived → published from snapshot).
Doesn't undo the deadlines reparent (live data didn't need one;
snapshot doesn't carry pre-state of deadlines).

Build + vet clean. TestMigrations_NoDuplicateSlot passes.

internal/db/migrations/152_dedupe_identical_sequencing_rule_clones.down.sql

@@ -0,0 +1,17 @@
+-- 152_dedupe_identical_sequencing_rule_clones (down) — t-paliad-321
+--
+-- Best-effort revert from paliad.sequencing_rules_pre_152. Flips the
+-- archived rows back to is_active=true / lifecycle_state='published'.
+-- Does NOT undo the deadlines.sequencing_rule_id reparent — that would
+-- require remembering the previous pointer per row, which the snapshot
+-- on sequencing_rules doesn't carry. In live data the reparent was a
+-- no-op (zero deadlines pointed at duplicates), so this is fine.
+
+UPDATE paliad.sequencing_rules sr
+   SET is_active = true,
+       lifecycle_state = 'published',
+       updated_at = now()
+  FROM paliad.sequencing_rules_pre_152 snap
+ WHERE sr.id = snap.id;
+
+DROP TABLE IF EXISTS paliad.sequencing_rules_pre_152;

internal/db/migrations/152_dedupe_identical_sequencing_rule_clones.up.sql

@@ -0,0 +1,240 @@
+-- 152_dedupe_identical_sequencing_rule_clones — t-paliad-321 / m/paliad#144 follow-up
+--
+-- Purpose: mig 151 archived 5 of 6 duplicate procedural_events for
+-- "Mängelbeseitigung / Zahlung" and reparented their sequencing_rules
+-- onto the canonical PE. The 6 sequencing_rules themselves remained
+-- active. Because every one of them is a byte-for-byte clone (same
+-- proceeding_type_id=NULL, rule_code=NULL, duration 14d, primary_party=NULL,
+-- everything else NULL, lifecycle_state='published') and only sequence_order
+-- differs, the admin shows six indistinguishable rows for one legal
+-- concept. This mig archives 5 of the 6 keeping the lexicographically
+-- lowest UUID as canonical.
+--
+-- Scope verified live before write (Supabase MCP, 2026-05-26):
+--   * Exactly 1 clone-group surfaces by the full-signature query
+--     below: 6 "Mängelbeseitigung / Zahlung" sequencing_rules with
+--     all-NULL discriminators and (duration_value=14, duration_unit='days').
+--   * 0 paliad.deadlines reference the 5 to-be-archived rows
+--     (verified via deadlines.sequencing_rule_id JOIN; the column
+--     formerly named deadlines.rule_id was dropped in mig 140 / B.4).
+--   * Other name-groups in the live corpus — "Antrag auf
+--     Patentänderung"×4, "Beginn des Hauptsacheverfahrens"×2,
+--     "Berufungsbegründung-R.220.1"×2, "Berufungsschrift-R.220.1"×2 —
+--     do NOT collapse under this signature because their
+--     proceeding_type_id / rule_code / duration / primary_party
+--     differ. They are legitimately distinct rules per proceeding;
+--     this mig leaves them alone.
+--
+-- Hard constraints honoured (mirrors mig 151):
+--   * No deletions. Archived rows flip to is_active=false +
+--     lifecycle_state='archived'. Rows stay in the table for audit.
+--   * Reparent paliad.deadlines.sequencing_rule_id duplicate →
+--     canonical BEFORE archiving, so no live deadline keeps pointing
+--     at an archived sequencing_rule. (deadlines.rule_id column
+--     dropped in mig 140; the back-link lives on sequencing_rule_id
+--     now — same UUID semantics.)
+--   * Snapshot the affected rows into paliad.sequencing_rules_pre_152
+--     in the same TX, mirroring precedent (migs 091/093/095/098/140/151).
+--   * set_config('paliad.audit_reason') is defensively called even
+--     though no audit trigger fires on sequencing_rules today (mig 151
+--     §comments documented this). Future audit trigger would inherit
+--     the reason automatically.
+--
+-- Generic-shape rationale: the audit query below uses the FULL
+-- signature paliadin specified — procedural_event_id, proceeding_type_id,
+-- rule_code, duration_value, duration_unit, primary_party, condition_expr,
+-- trigger_event_id, alt_*, anchor_alt, combine_op, parent_id, is_spawn,
+-- spawn_*. A NOTICE surfaces every group BEFORE the archive step so an
+-- operator running the deploy logs sees what's about to be touched.
+-- If new groups appear after future seeds, this mig is safe to re-run
+-- conceptually (it would archive any new clones) but only fires once
+-- via the applied_migrations protocol.
+
+-- ----------------------------------------------------------------
+-- 1. Build the dedupe mapping (duplicate_id → canonical_id) into a
+--    TEMP table used by every subsequent step.
+-- ----------------------------------------------------------------
+
+CREATE TEMP TABLE tmp_sr_dedupe ON COMMIT DROP AS
+WITH ranked AS (
+    SELECT
+        id, procedural_event_id, proceeding_type_id, rule_code,
+        duration_value, duration_unit, primary_party,
+        condition_expr, trigger_event_id, alt_duration_value,
+        alt_duration_unit, alt_rule_code, anchor_alt, combine_op,
+        parent_id, is_spawn, spawn_label, spawn_proceeding_type_id,
+        created_at,
+        ROW_NUMBER() OVER (
+            PARTITION BY
+                procedural_event_id, proceeding_type_id, rule_code,
+                duration_value, duration_unit, primary_party,
+                condition_expr::text, trigger_event_id,
+                alt_duration_value, alt_duration_unit, alt_rule_code,
+                anchor_alt, combine_op, parent_id, is_spawn, spawn_label,
+                spawn_proceeding_type_id
+            ORDER BY created_at, id::text
+        ) AS rn,
+        COUNT(*) OVER (
+            PARTITION BY
+                procedural_event_id, proceeding_type_id, rule_code,
+                duration_value, duration_unit, primary_party,
+                condition_expr::text, trigger_event_id,
+                alt_duration_value, alt_duration_unit, alt_rule_code,
+                anchor_alt, combine_op, parent_id, is_spawn, spawn_label,
+                spawn_proceeding_type_id
+        ) AS grp_size
+      FROM paliad.sequencing_rules
+     WHERE is_active = true
+       AND lifecycle_state = 'published'
+)
+SELECT
+    r.id AS duplicate_id,
+    canon.id AS canonical_id,
+    r.procedural_event_id,
+    (SELECT name FROM paliad.procedural_events WHERE id = r.procedural_event_id) AS pe_name
+  FROM ranked r
+  JOIN ranked canon
+    ON canon.procedural_event_id        IS NOT DISTINCT FROM r.procedural_event_id
+   AND canon.proceeding_type_id         IS NOT DISTINCT FROM r.proceeding_type_id
+   AND canon.rule_code                  IS NOT DISTINCT FROM r.rule_code
+   AND canon.duration_value             IS NOT DISTINCT FROM r.duration_value
+   AND canon.duration_unit              IS NOT DISTINCT FROM r.duration_unit
+   AND canon.primary_party              IS NOT DISTINCT FROM r.primary_party
+   AND canon.condition_expr::text       IS NOT DISTINCT FROM r.condition_expr::text
+   AND canon.trigger_event_id           IS NOT DISTINCT FROM r.trigger_event_id
+   AND canon.alt_duration_value         IS NOT DISTINCT FROM r.alt_duration_value
+   AND canon.alt_duration_unit          IS NOT DISTINCT FROM r.alt_duration_unit
+   AND canon.alt_rule_code              IS NOT DISTINCT FROM r.alt_rule_code
+   AND canon.anchor_alt                 IS NOT DISTINCT FROM r.anchor_alt
+   AND canon.combine_op                 IS NOT DISTINCT FROM r.combine_op
+   AND canon.parent_id                  IS NOT DISTINCT FROM r.parent_id
+   AND canon.is_spawn                   IS NOT DISTINCT FROM r.is_spawn
+   AND canon.spawn_label                IS NOT DISTINCT FROM r.spawn_label
+   AND canon.spawn_proceeding_type_id   IS NOT DISTINCT FROM r.spawn_proceeding_type_id
+   AND canon.rn = 1
+ WHERE r.rn > 1 AND r.grp_size > 1;
+
+-- ----------------------------------------------------------------
+-- 2. Surface every clone-group as a NOTICE before archiving.
+-- ----------------------------------------------------------------
+
+DO $$
+DECLARE
+    rec record;
+    total_to_archive int;
+BEGIN
+    SELECT COUNT(*) INTO total_to_archive FROM tmp_sr_dedupe;
+    RAISE NOTICE '[mig 152] PRE: % sequencing_rules row(s) will be archived', total_to_archive;
+    FOR rec IN
+        SELECT pe_name, canonical_id, COUNT(*) AS dup_count, array_agg(duplicate_id::text ORDER BY duplicate_id::text) AS dup_ids
+          FROM tmp_sr_dedupe
+         GROUP BY pe_name, canonical_id
+         ORDER BY pe_name
+    LOOP
+        RAISE NOTICE '[mig 152]   %  canonical=%  duplicates=%  ids=%',
+            rec.pe_name, rec.canonical_id, rec.dup_count, rec.dup_ids;
+    END LOOP;
+END $$;
+
+-- ----------------------------------------------------------------
+-- 3. Snapshot the rows about to be archived (only the duplicates;
+--    the canonicals stay in the live table). Matches precedent.
+-- ----------------------------------------------------------------
+
+CREATE TABLE paliad.sequencing_rules_pre_152 AS
+SELECT sr.*
+  FROM paliad.sequencing_rules sr
+  JOIN tmp_sr_dedupe d ON d.duplicate_id = sr.id;
+
+COMMENT ON TABLE paliad.sequencing_rules_pre_152 IS
+    'Snapshot of paliad.sequencing_rules rows archived by mig 152 '
+    '(identical clones — Mängelbeseitigung / Zahlung × 5). Mirrors '
+    'precedent pre_091/093/095/098/140/151. Read-only revert source. '
+    't-paliad-321 / m/paliad#144 follow-up.';
+
+-- ----------------------------------------------------------------
+-- 4. Reparent paliad.deadlines.sequencing_rule_id duplicate → canonical
+--    BEFORE archiving. Today's live data has 0 deadlines pointing at
+--    any duplicate, but the statement is safe + defensive against a
+--    race between drift-check and apply.
+-- ----------------------------------------------------------------
+
+UPDATE paliad.deadlines d
+   SET sequencing_rule_id = m.canonical_id,
+       procedural_event_id = (SELECT procedural_event_id
+                                FROM paliad.sequencing_rules
+                               WHERE id = m.canonical_id),
+       updated_at = now()
+  FROM tmp_sr_dedupe m
+ WHERE d.sequencing_rule_id = m.duplicate_id;
+
+-- ----------------------------------------------------------------
+-- 5. Defensive audit-reason. Sequencing_rules has no audit trigger
+--    today (mig 151 §scope verified), but set_config is transactional
+--    and a future audit trigger inherits the reason automatically.
+-- ----------------------------------------------------------------
+
+SELECT set_config('paliad.audit_reason',
+    'mig 152: archive identical sequencing_rule clones (mig 151 follow-up; t-paliad-321)',
+    true);
+
+-- ----------------------------------------------------------------
+-- 6. Archive the duplicates.
+-- ----------------------------------------------------------------
+
+UPDATE paliad.sequencing_rules
+   SET is_active = false,
+       lifecycle_state = 'archived',
+       updated_at = now()
+ WHERE id IN (SELECT duplicate_id FROM tmp_sr_dedupe);
+
+-- ----------------------------------------------------------------
+-- 7. POST assertions.
+-- ----------------------------------------------------------------
+
+DO $$
+DECLARE
+    v_archived int;
+    v_remaining_dupes int;
+    v_orphan_deadlines int;
+BEGIN
+    -- a. Did the expected number of rows get archived?
+    SELECT COUNT(*) INTO v_archived
+      FROM paliad.sequencing_rules
+     WHERE id IN (SELECT duplicate_id FROM tmp_sr_dedupe)
+       AND lifecycle_state = 'archived'
+       AND is_active = false;
+    IF v_archived <> (SELECT COUNT(*) FROM tmp_sr_dedupe) THEN
+        RAISE EXCEPTION '[mig 152] FAILED POST: expected % rows archived, got %',
+            (SELECT COUNT(*) FROM tmp_sr_dedupe), v_archived;
+    END IF;
+
+    -- b. No clone group of size > 1 should remain in active+published.
+    SELECT COUNT(*) INTO v_remaining_dupes FROM (
+        SELECT 1
+          FROM paliad.sequencing_rules
+         WHERE is_active = true AND lifecycle_state = 'published'
+         GROUP BY procedural_event_id, proceeding_type_id, rule_code,
+                  duration_value, duration_unit, primary_party,
+                  condition_expr::text, trigger_event_id,
+                  alt_duration_value, alt_duration_unit, alt_rule_code,
+                  anchor_alt, combine_op, parent_id, is_spawn, spawn_label,
+                  spawn_proceeding_type_id
+        HAVING COUNT(*) > 1
+    ) g;
+    IF v_remaining_dupes > 0 THEN
+        RAISE EXCEPTION '[mig 152] FAILED POST: % clone group(s) still active+published after archive', v_remaining_dupes;
+    END IF;
+
+    -- c. No deadline points at an archived sequencing_rule.
+    SELECT COUNT(*) INTO v_orphan_deadlines
+      FROM paliad.deadlines d
+      JOIN paliad.sequencing_rules sr ON sr.id = d.sequencing_rule_id
+     WHERE sr.lifecycle_state = 'archived';
+    IF v_orphan_deadlines > 0 THEN
+        RAISE EXCEPTION '[mig 152] FAILED POST: % live deadline(s) still point at an archived sequencing_rule', v_orphan_deadlines;
+    END IF;
+
+    RAISE NOTICE '[mig 152] OK — archived=%, remaining clone groups=0, orphan deadlines=0',
+        v_archived;
+END $$;