chore: convert submodules to standard directories for true monorepo structure

vibn-frontend/docker-compose.local-db.yml

@@ -0,0 +1,18 @@
+# Local-only Postgres for `next dev` + NextAuth (Prisma). Not for production.
+# Usage:
+#   docker compose -f docker-compose.local-db.yml up -d
+#   DATABASE_URL=postgresql://vibn:vibn@localhost:5433/vibn npx prisma db push
+services:
+  postgres:
+    image: postgres:16-alpine
+    ports:
+      - "5433:5432"
+    environment:
+      POSTGRES_USER: vibn
+      POSTGRES_PASSWORD: vibn
+      POSTGRES_DB: vibn
+    volumes:
+      - vibn_pg_local:/var/lib/postgresql/data
+
+volumes:
+  vibn_pg_local: