refactor(interests): migrate callers to interest_berths junction + drop berth_id

Phase 2b of the berth-recommender refactor (plan §3.4). Every caller of
the legacy `interests.berth_id` column now reads / writes through the
`interest_berths` junction via the helper service introduced in Phase 2a;
the column itself is dropped in a final migration.

Service-layer changes
- interests.service: filter `?berthId=X` becomes EXISTS-against-junction;
  list enrichment uses `getPrimaryBerthsForInterests`; create/update/
  linkBerth/unlinkBerth all dispatch through the junction helpers, with
  createInterest's row insert + junction write sharing a single transaction.
- clients / dashboard / report-generators / search: leftJoin chains pivot
  through `interest_berths` filtered by `is_primary=true`.
- eoi-context / document-templates / berth-rules-engine / portal /
  record-export / queue worker: read primary via `getPrimaryBerth(...)`.
- interest-scoring: berthLinked is now derived from any junction row count.
- dedup/migration-apply + public interest route: write a primary junction
  row alongside the interest insert when a berth is provided.

API contract preserved: list/detail responses still emit `berthId` and
`berthMooringNumber`, derived from the primary junction row, so frontend
consumers (interest-form, interest-detail-header) need no changes.

Schema + migration
- Drop `interestsRelations.berth` and `idx_interests_berth`.
- Replace `berthsRelations.interests` with `interestBerths`.
- Migration 0029_puzzling_romulus drops `interests.berth_id` + the index.
- Tests that previously inserted `interests.berthId` now seed a primary
  junction row alongside the interest.

Verified: vitest 995 passing (1 unrelated pre-existing flake in
maintenance-cleanup.test.ts), tsc clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lib/services/interest-berths.service.ts

@@ -22,6 +22,8 @@ import { db } from '@/lib/db';
 import { interestBerths, type InterestBerth } from '@/lib/db/schema/interests';
 import { berths } from '@/lib/db/schema/berths';
 
+type DbOrTx = typeof db | Parameters<Parameters<typeof db.transaction>[0]>[0];
+
 // ─── Reads ──────────────────────────────────────────────────────────────────
 
 export interface PrimaryBerthRef {
@@ -156,40 +158,54 @@ export async function upsertInterestBerth(
   opts: AddOrUpdateOpts = {},
 ): Promise<InterestBerth> {
   return db.transaction(async (tx) => {
-    if (opts.isPrimary === true) {
-      await tx
-        .update(interestBerths)
-        .set({ isPrimary: false })
-        .where(and(eq(interestBerths.interestId, interestId), eq(interestBerths.isPrimary, true)));
-    }
-    const setForUpdate: Partial<InterestBerth> = {};
-    if (opts.isPrimary !== undefined) setForUpdate.isPrimary = opts.isPrimary;
-    if (opts.isSpecificInterest !== undefined)
-      setForUpdate.isSpecificInterest = opts.isSpecificInterest;
-    if (opts.isInEoiBundle !== undefined) setForUpdate.isInEoiBundle = opts.isInEoiBundle;
-    if (opts.addedBy !== undefined) setForUpdate.addedBy = opts.addedBy;
-    if (opts.notes !== undefined) setForUpdate.notes = opts.notes;
-
-    const [row] = await tx
-      .insert(interestBerths)
-      .values({
-        interestId,
-        berthId,
-        isPrimary: opts.isPrimary ?? false,
-        isSpecificInterest: opts.isSpecificInterest ?? true,
-        isInEoiBundle: opts.isInEoiBundle ?? false,
-        addedBy: opts.addedBy,
-        notes: opts.notes,
-      })
-      .onConflictDoUpdate({
-        target: [interestBerths.interestId, interestBerths.berthId],
-        set: setForUpdate,
-      })
-      .returning();
-    return row!;
+    return upsertInterestBerthTx(tx, interestId, berthId, opts);
   });
 }
 
+/**
+ * Transaction-bound variant of {@link upsertInterestBerth}. Use this when the
+ * junction write must roll back together with another write (e.g. inserting
+ * the parent interest row in the same transaction).
+ */
+export async function upsertInterestBerthTx(
+  tx: DbOrTx,
+  interestId: string,
+  berthId: string,
+  opts: AddOrUpdateOpts = {},
+): Promise<InterestBerth> {
+  if (opts.isPrimary === true) {
+    await tx
+      .update(interestBerths)
+      .set({ isPrimary: false })
+      .where(and(eq(interestBerths.interestId, interestId), eq(interestBerths.isPrimary, true)));
+  }
+  const setForUpdate: Partial<InterestBerth> = {};
+  if (opts.isPrimary !== undefined) setForUpdate.isPrimary = opts.isPrimary;
+  if (opts.isSpecificInterest !== undefined)
+    setForUpdate.isSpecificInterest = opts.isSpecificInterest;
+  if (opts.isInEoiBundle !== undefined) setForUpdate.isInEoiBundle = opts.isInEoiBundle;
+  if (opts.addedBy !== undefined) setForUpdate.addedBy = opts.addedBy;
+  if (opts.notes !== undefined) setForUpdate.notes = opts.notes;
+
+  const [row] = await tx
+    .insert(interestBerths)
+    .values({
+      interestId,
+      berthId,
+      isPrimary: opts.isPrimary ?? false,
+      isSpecificInterest: opts.isSpecificInterest ?? true,
+      isInEoiBundle: opts.isInEoiBundle ?? false,
+      addedBy: opts.addedBy,
+      notes: opts.notes,
+    })
+    .onConflictDoUpdate({
+      target: [interestBerths.interestId, interestBerths.berthId],
+      set: setForUpdate,
+    })
+    .returning();
+  return row!;
+}
+
 /** Promote a single berth to primary for the interest. Demotes any prior primary. */
 export async function setPrimaryBerth(interestId: string, berthId: string): Promise<void> {
   await upsertInterestBerth(interestId, berthId, { isPrimary: true });