feat(04-01): multi-project schema migration — projects, settings, FK pivot

- schema.ts: add projects table, settings kv table, slug on clients;
  migrate 6 FK from client_id to project_id (phases, payments, documents, notes,
  time_entries, quote_items); update all relations and TypeScript types
- admin-queries.ts: fix getAllClientsWithPayments + getClientFullDetail to aggregate
  through projects; add getAllProjectsWithPayments, getProjectFullDetail,
  getClientWithProjects, ClientWithProjects type
- settings.ts: new file — getSetting, updateSetting, getTargetHourlyRate, SETTINGS_KEYS
- Fix all downstream files: actions.ts, quote-actions.ts, new/actions.ts,
  timer-actions.ts, approve/route.ts, comment/route.ts, TimerCell.tsx,
  analytics-queries.ts, client-view.ts, seed.ts
- DB migration applied to Coolify Postgres (all test data cleared, schema rebuilt)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/admin/layout.tsx

@@ -1,13 +1,16 @@
 import { NavBar } from "@/components/admin/NavBar";
+import { getServerSession } from "next-auth";
+import { authOptions } from "@/lib/auth";
 
-export default function AdminLayout({
+export default async function AdminLayout({
   children,
 }: {
   children: React.ReactNode;
 }) {
+  const session = await getServerSession(authOptions);
   return (
     <div className="min-h-screen bg-gray-50">
-      <NavBar />
+      {session && <NavBar />}
       <main className="max-w-5xl mx-auto px-6 py-8">{children}</main>
     </div>
   );