feat: add WonderQ admin backend

Add FastAPI admin/public API service, database setup, Docker deployment files, docs, and tests.

docker-compose.yml

@@ -0,0 +1,50 @@
+services:
+  api:
+    build: .
+    container_name: wonderq-admin-api
+    restart: unless-stopped
+    environment:
+      DATABASE_URL: postgresql://miniapp:miniapp_dev_password@postgres:5432/miniapp
+      JWT_SECRET: replace-with-a-long-random-secret-before-production
+      PORT: 4000
+      LOG_LEVEL: info
+    ports:
+      - "4000:4000"
+    depends_on:
+      postgres:
+        condition: service_healthy
+      redis:
+        condition: service_started
+    healthcheck:
+      test: ["CMD-SHELL", "curl -fsS http://localhost:4000/health || exit 1"]
+      interval: 10s
+      timeout: 5s
+      retries: 10
+
+  postgres:
+    image: postgres:16-alpine
+    container_name: wonderq-admin-postgres
+    restart: unless-stopped
+    environment:
+      POSTGRES_DB: miniapp
+      POSTGRES_USER: miniapp
+      POSTGRES_PASSWORD: miniapp_dev_password
+    ports:
+      - "5433:5432"
+    volumes:
+      - miniapp-postgres-data:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U miniapp -d miniapp"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+
+  redis:
+    image: redis:7-alpine
+    container_name: wonderq-admin-redis
+    restart: unless-stopped
+    ports:
+      - "6380:6379"
+
+volumes:
+  miniapp-postgres-data: