feat(registry): add service discovery and health check capabilities

- Integrate tonic-health for gRPC service health monitoring
- Add etcd-based service registration with automatic keep-alive
- Implement dynamic configuration loading from etcd with fallback
- Remove external dependencies from docker-compose for simplified deployment
- Refactor service registration logic with improved lease management
- Add health service to gRPC server with serving status reporting

docker-compose.yaml

@@ -14,7 +14,6 @@ x-appks-env: &appks-env
   APP_SESSION_COOKIE_PATH: /
   APP_SESSION_TTL_SECS: 86400
   APP_SESSION_MAX_AGE_SECS: 86400
-  # Postgres
   APP_DATABASE_URL: postgres://appks:appks@postgres:5432/appks
   DATABASE_URL: postgres://appks:appks@postgres:5432/appks
   APP_DATABASE_MAX_CONNECTIONS: 10
@@ -22,15 +21,11 @@ x-appks-env: &appks-env
   APP_DATABASE_IDLE_TIMEOUT: 600
   APP_DATABASE_MAX_LIFETIME: 3600
   APP_DATABASE_CONNECTION_TIMEOUT: 8
-  APP_DATABASE_SCHEMA_SEARCH_PATH: public
-  APP_DATABASE_READ_WRITE_SPLIT: "false"
   APP_DATABASE_RETRY_ATTEMPTS: 3
   APP_DATABASE_RETRY_DELAY: 5
-  # Redis (cluster mode)
   APP_REDIS_CLUSTER_ENABLED: "true"
   APP_REDIS_CLUSTER_NODES: redis://redis-node-0:6379,redis://redis-node-1:6379,redis://redis-node-2:6379,redis://redis-node-3:6379,redis://redis-node-4:6379,redis://redis-node-5:6379
   APP_REDIS_READ_FROM_REPLICAS: "false"
-  APP_REDIS_PASSWORD: ""
   APP_REDIS_MAX_CONNECTIONS: 20
   APP_REDIS_MIN_CONNECTIONS: 2
   APP_REDIS_IDLE_TIMEOUT: 300
@@ -39,7 +34,6 @@ x-appks-env: &appks-env
   APP_REDIS_RETRY_DELAY_MS: 100
   APP_REDIS_TLS_ENABLED: "false"
   APP_REDIS_KEY_PREFIX: "appks:"
-  # etcd
   APP_ETCD_ENDPOINTS: http://etcd:2379
   APP_ETCD_KEY_PREFIX: /appks/
   APP_ETCD_CONNECT_TIMEOUT: 5
@@ -48,7 +42,6 @@ x-appks-env: &appks-env
   APP_ETCD_LEASE_TTL: 15
   APP_ETCD_MAX_RETRIES: 3
   APP_ETCD_REGISTER_SELF: "true"
-  # NATS
   APP_NATS_URL: nats://nats:4222
   APP_NATS_CONNECTION_TIMEOUT: 5
   APP_NATS_PING_INTERVAL: 20
@@ -57,7 +50,6 @@ x-appks-env: &appks-env
   APP_NATS_STREAM_PREFIX: APPKS
   APP_NATS_ACK_WAIT_SECS: 30
   APP_NATS_MAX_DELIVER: 5
-  # S3 / MinIO
   APP_S3_ENDPOINT: http://minio:9000
   APP_S3_REGION: us-east-1
   APP_S3_ACCESS_KEY: admin
@@ -73,34 +65,16 @@ x-appks-env: &appks-env
   APP_S3_UPLOAD_PART_SIZE: 8388608
   APP_S3_MAX_UPLOAD_SIZE: 104857600
   APP_S3_PRESIGNED_URL_EXPIRY: 3600
-  # LRU cache
   APP_LRU_DEFAULT_CAPACITY: 1000
   APP_LRU_DEFAULT_TTL_SECS: 300
   APP_LRU_CLEANUP_INTERVAL_SECS: 60
-  # gRPC
   APP_RPC_SELF_HOST: 0.0.0.0
   APP_RPC_SELF_PORT: 50049
   APP_RPC_SELF_REFLECTION: "false"
   APP_RPC_SELF_SERVICE_NAME: appks
   APP_RPC_DEFAULT_TIMEOUT_SECS: 10
-  # AI (disabled by default in compose — set externally)
-  APP_AI_PROVIDER_API_KEY: ""
-  APP_AI_PROVIDER_URL: ""
-  # Qdrant
-  APP_QDRANT_URL: http://qdrant:6334
-  APP_QDRANT_COLLECTION: appks_embeddings
-  APP_QDRANT_VECTOR_SIZE: 1536
-  APP_QDRANT_DISTANCE: Cosine
-  APP_QDRANT_MAX_CONNECTIONS: 10
-  APP_QDRANT_IDLE_TIMEOUT: 300
-  APP_QDRANT_CONNECTION_TIMEOUT: 10
-  APP_QDRANT_MAX_RETRIES: 3
-  APP_QDRANT_TLS_ENABLED: "false"
-  APP_QDRANT_SEARCH_LIMIT: 10
-  APP_QDRANT_SCORE_THRESHOLD: 0.7
 
 services:
-  # AppKS
   appks:
     image: appks
     restart: unless-stopped
@@ -109,232 +83,3 @@ services:
       - "50049:50049"
     environment:
       <<: *appks-env
-    depends_on:
-      postgres:
-        condition: service_healthy
-      etcd:
-        condition: service_started
-      nats:
-        condition: service_started
-      minio:
-        condition: service_healthy
-      qdrant:
-        condition: service_started
-    networks:
-      - appks-net
-
-  # PostgreSQL
-  postgres:
-    image: postgres:17-alpine
-    restart: unless-stopped
-    environment:
-      POSTGRES_USER: appks
-      POSTGRES_PASSWORD: appks
-      POSTGRES_DB: appks
-    ports:
-      - "5432:5432"
-    volumes:
-      - pg_data:/var/lib/postgresql/data
-    healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U appks -d appks"]
-      interval: 5s
-      timeout: 5s
-      retries: 5
-    networks:
-      - appks-net
-
-  # Redis Cluster (6 nodes)
-  redis-node-0:
-    image: redis:7-alpine
-    command: redis-server --port 6379 --cluster-enabled yes --cluster-config-file nodes.conf --cluster-node-timeout 5000 --appendonly yes
-    restart: unless-stopped
-    ports:
-      - "6379:6379"
-    volumes:
-      - redis_data_0:/data
-    networks:
-      - appks-net
-
-  redis-node-1:
-    image: redis:7-alpine
-    command: redis-server --port 6379 --cluster-enabled yes --cluster-config-file nodes.conf --cluster-node-timeout 5000 --appendonly yes
-    restart: unless-stopped
-    ports:
-      - "6380:6379"
-    volumes:
-      - redis_data_1:/data
-    networks:
-      - appks-net
-
-  redis-node-2:
-    image: redis:7-alpine
-    command: redis-server --port 6379 --cluster-enabled yes --cluster-config-file nodes.conf --cluster-node-timeout 5000 --appendonly yes
-    restart: unless-stopped
-    ports:
-      - "6381:6379"
-    volumes:
-      - redis_data_2:/data
-    networks:
-      - appks-net
-
-  redis-node-3:
-    image: redis:7-alpine
-    command: redis-server --port 6379 --cluster-enabled yes --cluster-config-file nodes.conf --cluster-node-timeout 5000 --appendonly yes
-    restart: unless-stopped
-    ports:
-      - "6382:6379"
-    volumes:
-      - redis_data_3:/data
-    networks:
-      - appks-net
-
-  redis-node-4:
-    image: redis:7-alpine
-    command: redis-server --port 6379 --cluster-enabled yes --cluster-config-file nodes.conf --cluster-node-timeout 5000 --appendonly yes
-    restart: unless-stopped
-    ports:
-      - "6383:6379"
-    volumes:
-      - redis_data_4:/data
-    networks:
-      - appks-net
-
-  redis-node-5:
-    image: redis:7-alpine
-    command: redis-server --port 6379 --cluster-enabled yes --cluster-config-file nodes.conf --cluster-node-timeout 5000 --appendonly yes
-    restart: unless-stopped
-    ports:
-      - "6384:6379"
-    volumes:
-      - redis_data_5:/data
-    networks:
-      - appks-net
-
-  redis-cluster-init:
-    image: redis:7-alpine
-    depends_on:
-      - redis-node-0
-      - redis-node-1
-      - redis-node-2
-      - redis-node-3
-      - redis-node-4
-      - redis-node-5
-    entrypoint: >
-      sh -c '
-        echo "Waiting for all Redis nodes to be ready...";
-        sleep 5;
-        echo "Creating Redis cluster...";
-        redis-cli --cluster create
-          redis-node-0:6379
-          redis-node-1:6379
-          redis-node-2:6379
-          redis-node-3:6379
-          redis-node-4:6379
-          redis-node-5:6379
-          --cluster-replicas 1
-          --cluster-yes
-        '
-    networks:
-      - appks-net
-
-  # etcd
-  etcd:
-    image: quay.io/coreos/etcd:v3.5
-    restart: unless-stopped
-    command: >
-      etcd
-      --name etcd
-      --data-dir /etcd-data
-      --listen-client-urls http://0.0.0.0:2379
-      --advertise-client-urls http://etcd:2379
-      --listen-peer-urls http://0.0.0.0:2380
-      --initial-advertise-peer-urls http://etcd:2380
-      --initial-cluster etcd=http://etcd:2380
-      --initial-cluster-token appks-etcd
-      --initial-cluster-state new
-    ports:
-      - "2379:2379"
-      - "2380:2380"
-    volumes:
-      - etcd_data:/etcd-data
-    networks:
-      - appks-net
-
-  # NATS
-  nats:
-    image: nats:2-alpine
-    restart: unless-stopped
-    command: --js --store_dir /data/nats
-    ports:
-      - "4222:4222"
-      - "8222:8222"
-    volumes:
-      - nats_data:/data/nats
-    networks:
-      - appks-net
-
-  # MinIO (S3-compatible storage)
-  minio:
-    image: minio/minio:latest
-    restart: unless-stopped
-    command: server /data --console-address ":9001"
-    environment:
-      MINIO_ROOT_USER: admin
-      MINIO_ROOT_PASSWORD: mysecret123
-    ports:
-      - "9000:9000"
-      - "9001:9001"
-    volumes:
-      - minio_data:/data
-    healthcheck:
-      test: ["CMD-SHELL", "mc ready local || exit 1"]
-      interval: 5s
-      timeout: 5s
-      retries: 5
-    networks:
-      - appks-net
-
-  # MinIO bucket auto-creation
-  minio-init:
-    image: minio/mc:latest
-    depends_on:
-      minio:
-        condition: service_healthy
-    entrypoint: >
-      sh -c '
-        mc alias set local http://minio:9000 admin mysecret123;
-        mc mb --ignore-existing local/appks;
-        echo "MinIO bucket appks ready";
-        exit 0
-      '
-    networks:
-      - appks-net
-
-  # Qdrant (vector database)
-  qdrant:
-    image: qdrant/qdrant:latest
-    restart: unless-stopped
-    ports:
-      - "6333:6333"
-      - "6334:6334"
-    volumes:
-      - qdrant_data:/qdrant/storage
-    networks:
-      - appks-net
-
-volumes:
-  pg_data:
-  redis_data_0:
-  redis_data_1:
-  redis_data_2:
-  redis_data_3:
-  redis_data_4:
-  redis_data_5:
-  etcd_data:
-  nats_data:
-  minio_data:
-  qdrant_data:
-
-networks:
-  appks-net:
-    driver: bridge