feat: UAT environment setup with separate PocketBase instance

- Add UAT PocketBase on port 8712 with separate pb_data_uat
- Add UAT nginx config proxying to UAT PB (port 8712)
- Update Dockerfile to support NGINX_CONF build arg
- Add .gitignore for .playwright-mcp/
- Auto-generated team_sessions migration

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docker-compose.uat.yml

@@ -1,14 +1,39 @@
 services:
+  pocketbase-uat:
+    image: ghcr.io/muchobien/pocketbase:0.22.4
+    container_name: gamegroup-pb-uat
+    ports:
+      - "8712:8090"
+    volumes:
+      - ./backend/pb_data_uat:/pb_data
+      - ./backend/pb_migrations:/pb_migrations
+      - ./backend/pb_hooks:/pb_hooks
+    environment:
+      - GO_ENV=production
+    restart: unless-stopped
+    healthcheck:
+      test: ["CMD", "wget", "--no-verbose", "--tries=1", "--spider", "http://localhost:8090/api/health"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 40s
+    networks:
+      - gamegroup-net
+
   frontend-uat:
     build:
       context: ./frontend
       dockerfile: Dockerfile
+      args:
+        NGINX_CONF: nginx.uat.conf
     container_name: gamegroup-frontend-uat
     ports:
       - "7034:80"
     environment:
       - NODE_ENV=production
     restart: unless-stopped
+    depends_on:
+      - pocketbase-uat
     networks:
       - gamegroup-net