feat(berths): split Documents tab into Spec + Deal Documents

Berth detail page now has two tabs:
  - Spec: the existing versioned berth-spec PDF surface (current panel,
    version history, parser badge).
  - Deal Documents: NEW. Lists EOIs / contracts / etc. attached to
    interests currently linked to this berth via interest_berths.

New service helper listDealDocumentsForBerth joins documents →
interests → interest_berths with a port_id guard on both sides.
GET /api/v1/berths/[id]/deal-documents wraps it, gated on berths.view.

Read-only — title, type, status badge, and an Open link to the source
interest page. Edits / sends still happen on the interest's own page.
The Spec tab paragraph now points reps to the new Deal Documents tab
instead of telling them to navigate via Interests.

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

src/components/berths/berth-tabs.tsx

@@ -23,6 +23,7 @@ import { BerthReservationsTab } from './berth-reservations-tab';
 import { BerthInterestsTab } from './berth-interests-tab';
 import { BerthInterestPulse } from './berth-interest-pulse';
 import { BerthDocumentsTab } from './berth-documents-tab';
+import { BerthDealDocumentsTab } from './berth-deal-documents-tab';
 
 type BerthData = {
   id: string;
@@ -413,10 +414,15 @@ export function buildBerthTabs(berth: BerthData): DetailTab[] {
       content: <BerthReservationsTab berthId={berth.id} />,
     },
     {
-      id: 'documents',
-      label: 'Documents',
+      id: 'spec',
+      label: 'Spec',
       content: <BerthDocumentsTab berthId={berth.id} />,
     },
+    {
+      id: 'deal-documents',
+      label: 'Deal Documents',
+      content: <BerthDealDocumentsTab berthId={berth.id} />,
+    },
     // Waiting List + Maintenance Log tabs were stubs ("coming soon")
     // visible to every operator. Hidden here until the
     // berth_waiting_list / berth_maintenance_log feature surfaces ship.