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/src/db/all-schema.ts

@@ -0,0 +1,6 @@
+export * from './schema.js';
+export * from '../domains/couples/schema.js';
+export * from '../domains/packs/schema.js';
+export * from '../domains/answers/schema.js';
+export * from '../domains/chat/schema.js';
+export * from '../domains/app-data/schema.js';