feat(backend): add standalone data plane

Replace the Supabase application data plane with the Node/PostgreSQL API, migrate mobile, admin, web, and MCP callers, add controlled cutover tooling, and define hardened Dokploy infrastructure.

apps/api/drizzle.config.ts

@@ -0,0 +1,14 @@
+import { defineConfig } from 'drizzle-kit';
+
+if (!process.env.DATABASE_URL) {
+  throw new Error('DATABASE_URL is required for database migrations');
+}
+
+export default defineConfig({
+  dialect: 'postgresql',
+  schema: './src/db/all-schema.ts',
+  out: './drizzle',
+  dbCredentials: { url: process.env.DATABASE_URL },
+  strict: true,
+  verbose: true,
+});