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/dashboard.service.ts

@@ -2,7 +2,7 @@ import { and, count, desc, eq, isNull, sql } from 'drizzle-orm';
 
 import { db } from '@/lib/db';
 import { clients } from '@/lib/db/schema/clients';
-import { interests } from '@/lib/db/schema/interests';
+import { interests, interestBerths } from '@/lib/db/schema/interests';
 import { berths } from '@/lib/db/schema/berths';
 import { systemSettings, auditLogs } from '@/lib/db/schema/system';
 import { PIPELINE_STAGES, STAGE_WEIGHTS } from '@/lib/constants';
@@ -29,19 +29,17 @@ export async function getKpis(portId: string) {
 
   // Pipeline value: SUM each berth's price ONCE regardless of how many active
   // interests reference it. A berth with multiple interests would otherwise be
-  // counted multiple times, inflating the total.
+  // counted multiple times, inflating the total. Reads the primary-berth link
+  // via interest_berths (plan §3.4).
   const pipelineRows = await db
-    .selectDistinct({ berthId: interests.berthId, price: berths.price })
+    .selectDistinct({ berthId: interestBerths.berthId, price: berths.price })
     .from(interests)
-    .innerJoin(berths, eq(interests.berthId, berths.id))
-    .where(
-      and(
-        eq(interests.portId, portId),
-        isNull(interests.archivedAt),
-        isActiveInterest,
-        sql`${interests.berthId} IS NOT NULL`,
-      ),
-    );
+    .innerJoin(
+      interestBerths,
+      and(eq(interestBerths.interestId, interests.id), eq(interestBerths.isPrimary, true)),
+    )
+    .innerJoin(berths, eq(interestBerths.berthId, berths.id))
+    .where(and(eq(interests.portId, portId), isNull(interests.archivedAt), isActiveInterest));
 
   const pipelineValueUsd = pipelineRows.reduce((acc, row) => {
     return acc + (row.price ? parseFloat(String(row.price)) : 0);
@@ -111,7 +109,8 @@ export async function getRevenueForecast(portId: string) {
   }
 
   // Forecast excludes lost/cancelled - only currently-active or won-out
-  // interests should affect the weighted pipeline value.
+  // interests should affect the weighted pipeline value. Reads the
+  // primary-berth link via interest_berths (plan §3.4).
   const interestRows = await db
     .select({
       id: interests.id,
@@ -119,15 +118,12 @@ export async function getRevenueForecast(portId: string) {
       berthPrice: berths.price,
     })
     .from(interests)
-    .innerJoin(berths, eq(interests.berthId, berths.id))
-    .where(
-      and(
-        eq(interests.portId, portId),
-        isNull(interests.archivedAt),
-        isActiveInterest,
-        sql`${interests.berthId} IS NOT NULL`,
-      ),
-    );
+    .innerJoin(
+      interestBerths,
+      and(eq(interestBerths.interestId, interests.id), eq(interestBerths.isPrimary, true)),
+    )
+    .innerJoin(berths, eq(interestBerths.berthId, berths.id))
+    .where(and(eq(interests.portId, portId), isNull(interests.archivedAt), isActiveInterest));
 
   // Build stageBreakdown
   const stageMap: Record<string, { count: number; weightedValue: number }> = {};