feat: add multi-environment deployment with Gitea Actions & Dokploy

- Update Gitea workflow to build dev/staging/main branches
- Create environment-specific docker-compose files
  - docker-compose.dev.yml (pulls dev image)
  - docker-compose.staging.yml (pulls staging image)
  - docker-compose.prod.yml (pulls latest image)
  - docker-compose.local.yml (builds locally for development)
- Remove generic docker-compose.yml (replaced by env-specific files)
- Update .dockerignore to exclude docs/ and .gitea/ from production images
- Add comprehensive deployment guide (docs/DOKPLOY_DEPLOYMENT.md)

Image Tags:
- dev branch → :dev
- staging branch → :staging
- main branch → :latest
- All branches → :{branch}-{sha}

Benefits:
- Separate deployments for dev/staging/prod
- Automated CI/CD via Gitea Actions + Dokploy webhooks
- Leaner production images (excludes dev tools/docs)
- Local development support (docker-compose.local.yml)
- Rollback support via SHA-tagged images

docker-compose.local.yml

@@ -0,0 +1,43 @@
+version: "3.8"
+
+services:
+  ai-stack-deployer:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    container_name: ai-stack-deployer-local
+    ports:
+      - "3000:3000"
+    environment:
+      - NODE_ENV=development
+      - PORT=3000
+      - HOST=0.0.0.0
+      - DOKPLOY_URL=${DOKPLOY_URL}
+      - DOKPLOY_API_TOKEN=${DOKPLOY_API_TOKEN}
+      - STACK_DOMAIN_SUFFIX=${STACK_DOMAIN_SUFFIX:-ai.flexinit.nl}
+      - STACK_IMAGE=${STACK_IMAGE:-git.app.flexinit.nl/flexinit/agent-stack:latest}
+      - RESERVED_NAMES=${RESERVED_NAMES:-admin,api,www,root,system,test,demo,portal}
+    env_file:
+      - .env
+    restart: unless-stopped
+    healthcheck:
+      test:
+        [
+          "CMD",
+          "bun",
+          "--eval",
+          "fetch('http://localhost:3000/health').then(r => process.exit(r.ok ? 0 : 1)).catch(() => process.exit(1))",
+        ]
+      interval: 30s
+      timeout: 3s
+      retries: 3
+      start_period: 5s
+    networks:
+      - ai-stack-network
+    volumes:
+      - ./src:/app/src:ro
+      - ./client:/app/client:ro
+
+networks:
+  ai-stack-network:
+    driver: bridge