feat(documents): hub page with tabs, filters, and live counts

Replaces /documents with the Phase A hub: tabs (All/Awaiting them/
Awaiting me/Completed/Expired) backed by per-tab counts via a new
hub-counts endpoint, signature-only chip, type filter, expandable
signer rows, and real-time invalidation across the eight document
socket events. listDocuments grew tab/watcher/signatureOnly/sent-window
filters; the legacy file browser moved to /documents/files where the
sidebar already linked.

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

src/app/api/v1/documents/hub-counts/route.ts

@@ -0,0 +1,16 @@
+import { NextResponse } from 'next/server';
+
+import { withAuth, withPermission } from '@/lib/api/helpers';
+import { errorResponse } from '@/lib/errors';
+import { getHubTabCounts } from '@/lib/services/documents.service';
+
+export const GET = withAuth(
+  withPermission('documents', 'view', async (_req, ctx) => {
+    try {
+      const counts = await getHubTabCounts(ctx.portId, ctx.user.email);
+      return NextResponse.json({ data: counts });
+    } catch (error) {
+      return errorResponse(error);
+    }
+  }),
+);

src/app/api/v1/documents/route.ts

@@ -10,7 +10,9 @@ export const GET = withAuth(
   withPermission('documents', 'view', async (req, ctx) => {
     try {
       const query = parseQuery(req, listDocumentsSchema);
-      const result = await listDocuments(ctx.portId, query);
+      const result = await listDocuments(ctx.portId, query, {
+        currentUserEmail: ctx.user.email,
+      });
 
       const { page, limit } = query;
       const totalPages = Math.ceil(result.total / limit);