feat(uat-batch): Group I — Residential parity (4 ships)

I34–I37 from the 2026-05-21 plan.

Shipped:
  I34  Residential client header layout parity. Email / Call /
       WhatsApp action buttons mirror the main ClientDetailHeader.
       WhatsApp number resolves from phoneE164 (preferred) or strips
       the free-text phone to digits. Header surfaces "Linked to
       main client" chip when the auto-link matcher (I37) finds a
       counterpart in the main CRM.
  I35  Residential interests list rebuilt for parity with the main
       InterestList. New ResidentialInterestCard +
       getResidentialInterestColumns + residentialInterestFilter-
       Definitions; the list page drives DataTable + FilterBar +
       ColumnPicker + SavedViewsDropdown + bulkActions. List
       endpoint validator widened to accept pipelineStage as a
       string OR string[] and added a source filter. Service post-
       fetches client names via a single IN-list lookup so the
       table renders fullName in column 1 without N+1.
       New /api/v1/residential/interests/bulk supports
       change_stage + archive (100-id cap). Kanban view deferred.
  I36  Residential inquiries auto-forward to partner email(s).
       New registry entry residential_partner_recipients (comma-
       separated) under section residential.partner.
       createResidentialInterest fires
       forwardResidentialInquiryToPartner after the row lands.
       Helper uses the same branded shell other transactional
       emails use. Failures log + never block create. The
       /admin/residential-stages page picks up a registry-driven
       card so admins manage recipients alongside stages.
  I37  Auto-link residential ↔ main client. Migration 0080 adds
       residential_clients.linked_client_id (nullable FK, SET NULL
       on cascade) + partial index. New findAndLinkMatchingMainClient
       service matches by email first (case-insensitive client_contacts
       lookup) then by E.164 phone. First exact match wins. Fires
       fire-and-forget from createResidentialClient. Header surfaces
       the link via a "Linked to main client" chip. Backfill script
       + reverse-direction link from main ClientDetailHeader stay
       as follow-ups.

Verified: tsc clean, vitest 1454/1454, migration applied.

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

src/lib/db/migrations/0080_residential_linked_client.sql

@@ -0,0 +1,18 @@
+-- 2026-05-21: residential ↔ main-client auto-link.
+--
+-- Adds a nullable FK from `residential_clients` to the main `clients`
+-- table. When the matching service finds a main-client record with the
+-- same email / E.164 phone, the residential row is linked so reps can
+-- see the cross-record relationship from either side without manual
+-- de-duplication.
+--
+-- ON DELETE SET NULL keeps the residential record intact even if the
+-- main client is hard-deleted (GDPR wipe etc.). Index supports
+-- "what residential rows are linked to this main client" queries.
+
+ALTER TABLE residential_clients
+  ADD COLUMN linked_client_id text REFERENCES clients(id) ON DELETE SET NULL;
+
+CREATE INDEX IF NOT EXISTS idx_residential_clients_linked_client
+  ON residential_clients (linked_client_id)
+  WHERE linked_client_id IS NOT NULL;

src/lib/db/schema/residential.ts

@@ -44,6 +44,14 @@ export const residentialClients = pgTable(
     status: text('status').notNull().default('prospect'),
     source: text('source'), // website | manual | referral | broker
     notes: text('notes'),
+    /**
+     * Optional link to a matching record in the main `clients` table.
+     * Populated by `findAndLinkMatchingMainClient` after create, or
+     * manually via the admin UI. ON DELETE SET NULL — the residential
+     * record outlives a GDPR wipe of the main client. Migration 0080
+     * adds the FK + supporting index.
+     */
+    linkedClientId: text('linked_client_id'),
     archivedAt: timestamp('archived_at', { withTimezone: true }),
     createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
     updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
@@ -54,6 +62,9 @@ export const residentialClients = pgTable(
     index('idx_residential_clients_archived')
       .on(table.portId)
       .where(sql`${table.archivedAt} IS NULL`),
+    index('idx_residential_clients_linked_client')
+      .on(table.linkedClientId)
+      .where(sql`${table.linkedClientId} IS NOT NULL`),
   ],
 );