T1/Phase 1: scaffold Vite SPA + Hono API + Bun worker

- apps/web: Vite + React 19 + TanStack Router/Query + shadcn/ui
   - apps/api: Hono + Bun on :3001 with /api/health, /api/auth/*, /mcp stubs
   - apps/worker: Bun worker stub, DB connection, graceful SIGTERM
   - apps/web-legacy/: old Next.js code moved aside (preserved for T2-T8 reference)
   - Dockerfiles: api (Bun), worker (Bun), spa (multi-stage Caddy)
   - Caddyfile: serves dist + reverse-proxies /api/* + /mcp to api
   - docker-compose.yml: 4-service target (api, spa, db, worker)
   - packages/db/src/client.ts: shared Drizzle client for api + worker
   - db/client.ts: root-level alias for convenience

   Parent: t_e1cbd87d -> t_24c9c3fd (T0)

apps/web-legacy/app/api/domains/[domainId]/activity/route.ts

@@ -0,0 +1,47 @@
+// AGENT INSTRUCTION: After every write (INSERT/UPDATE/DELETE), you MUST:
+// 1. Insert activity feed entry
+// 2. Call pg.notify('project_e_events', JSON.stringify({ type, action, id, workspace_id }))
+// See AGENTS.md for full rules.
+
+import { NextRequest, NextResponse } from 'next/server';
+import { withAuth, requireWorkspaceAccess, createErrorResponse } from '@/lib/auth';
+import { db, activityFeed } from '@project-e/db';
+import { and, desc, eq, sql } from 'drizzle-orm';
+
+type RouteContext = { params: Promise<{ domainId: string }> };
+
+// GET /api/domains/[domainId]/activity — List activity feed for a workspace
+export const GET = withAuth<RouteContext>(async (request: NextRequest, user, context) => {
+  const { domainId } = await context!.params;
+  await requireWorkspaceAccess(domainId);
+
+  const { searchParams } = new URL(request.url);
+  const entityType = searchParams.get('entity_type');
+  const limit = Math.min(parseInt(searchParams.get('limit') || '20'), 100);
+  const offset = parseInt(searchParams.get('offset') || '0');
+
+  const conditions: any[] = [eq(activityFeed.workspaceId, domainId)];
+
+  if (entityType) {
+    conditions.push(eq(activityFeed.entityType, entityType));
+  }
+
+  const [items, countResult] = await Promise.all([
+    db.select()
+      .from(activityFeed)
+      .where(and(...conditions))
+      .orderBy(desc(activityFeed.createdAt))
+      .limit(limit)
+      .offset(offset),
+    db.select({ count: sql<number>`count(*)` })
+      .from(activityFeed)
+      .where(and(...conditions)),
+  ]);
+
+  return NextResponse.json({
+    items,
+    totalItems: Number(countResult[0]?.count || 0),
+    limit,
+    offset,
+  });
+});