refactor: remove batch mode, simplify to API-only deployment

Removes dual-mode deployment complexity, focusing on REST API service only.

Changes:
- Removed batch mode from docker-compose.yml (now single ai-trader service)
- Deleted scripts/test_batch_mode.sh validation script
- Renamed entrypoint-api.sh to entrypoint.sh (now default)
- Simplified Dockerfile (single entrypoint, removed CMD)
- Updated validation scripts to use 'ai-trader' service name
- Updated documentation (README.md, TESTING_GUIDE.md, CHANGELOG.md)

Benefits:
- Eliminates port conflicts between batch and API services
- Simpler configuration and deployment
- API-first architecture aligned with Windmill integration
- Reduced maintenance complexity

Breaking Changes:
- Batch mode no longer available
- All simulations must use REST API endpoints

docker-compose.yml

@@ -1,52 +1,10 @@
 services:
-  # Batch mode: Run one-time simulations with config file
-  ai-trader-batch:
+  # REST API server for Windmill integration
+  ai-trader:
     # image: ghcr.io/xe138/ai-trader:latest
     # Uncomment to build locally instead of pulling:
     build: .
-    container_name: ai-trader-batch
-    volumes:
-      - ${VOLUME_PATH:-.}/data:/app/data
-      - ${VOLUME_PATH:-.}/logs:/app/logs
-      - ${VOLUME_PATH:-.}/configs:/app/configs
-    environment:
-      # AI Model API Configuration
-      - OPENAI_API_BASE=${OPENAI_API_BASE}
-      - OPENAI_API_KEY=${OPENAI_API_KEY}
-
-      # Data Source Configuration
-      - ALPHAADVANTAGE_API_KEY=${ALPHAADVANTAGE_API_KEY}
-      - JINA_API_KEY=${JINA_API_KEY}
-
-      # System Configuration
-      - RUNTIME_ENV_PATH=/app/data/runtime_env.json
-
-      # MCP Service Ports (fixed internally)
-      - MATH_HTTP_PORT=8000
-      - SEARCH_HTTP_PORT=8001
-      - TRADE_HTTP_PORT=8002
-      - GETPRICE_HTTP_PORT=8003
-
-      # Agent Configuration
-      - AGENT_MAX_STEP=${AGENT_MAX_STEP:-30}
-    ports:
-      # Format: "HOST:CONTAINER" - container ports are fixed, host ports configurable via .env
-      - "${MATH_HTTP_PORT:-8000}:8000"
-      - "${SEARCH_HTTP_PORT:-8001}:8001"
-      - "${TRADE_HTTP_PORT:-8002}:8002"
-      - "${GETPRICE_HTTP_PORT:-8003}:8003"
-      - "${WEB_HTTP_PORT:-8888}:8888"
-    restart: "no"  # Batch jobs should not auto-restart
-    profiles:
-      - batch  # Only start with: docker-compose --profile batch up
-
-  # API mode: REST API server for Windmill integration
-  ai-trader-api:
-    # image: ghcr.io/xe138/ai-trader:latest
-    # Uncomment to build locally instead of pulling:
-    build: .
-    container_name: ai-trader-api
-    entrypoint: ["./entrypoint-api.sh"]
+    container_name: ai-trader
     volumes:
       - ${VOLUME_PATH:-.}/data:/app/data
       - ${VOLUME_PATH:-.}/logs:/app/logs