feat: 新增 core/agents 模块和 nanobot

- 新增 agents 模块，包含 agent、api、skills 等子模块
- 新增 nanobot 项目，支持多渠道集成
- 添加启动脚本 start-all.bat 和 start-all.sh

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/agents/main.py

@@ -0,0 +1,165 @@
+"""Main entry point for X-Agents agent service."""
+
+import logging
+import asyncio
+import sys
+from pathlib import Path
+
+# Add project root to path (parent of core directory)
+project_root = Path(__file__).parent.parent.parent
+core_dir = project_root / "core"
+sys.path.insert(0, str(project_root))  # for X-Agents root
+sys.path.insert(0, str(core_dir))      # for core
+sys.path.insert(0, str(core_dir / "nanobot"))  # for nanobot
+
+from fastapi import FastAPI
+import uvicorn
+
+from agents.config import Config
+from agents.api.routes import router, set_agent, set_team_agent, add_cors
+from agents.agent.loop import AgentLoop
+from agents.agent.team_agent import TeamAgent
+from agents.llm import ProviderFactory
+from agents.tools import create_default_registry
+
+# Configure logging
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
+)
+logger = logging.getLogger(__name__)
+
+
+class SimpleProvider:
+    """Simple LLM provider placeholder for testing without API keys."""
+
+    def __init__(self, api_key: str = "", base_url: str | None = None):
+        self.api_key = api_key
+        self.base_url = base_url
+
+    async def chat(self, messages: list[dict], model: str, **kwargs) -> dict:
+        """Simulate LLM chat response.
+
+        Args:
+            messages: Message list
+            model: Model name
+
+        Returns:
+            Simulated response
+        """
+        from agents.llm import LLMResponse
+
+        user_msg = ""
+        for msg in reversed(messages):
+            if msg.get("role") == "user":
+                user_msg = msg.get("content", "")
+                break
+
+        return LLMResponse(
+            content=f"I received your message: {user_msg[:50]}... (LLM integration pending)",
+            tool_calls=[],
+            finish_reason="stop",
+        )
+
+    async def chat_with_retry(self, *args, **kwargs):
+        return await self.chat(*args, **kwargs)
+
+    def get_default_model(self) -> str:
+        return "simple"
+
+
+def create_app(config: Config | None = None) -> FastAPI:
+    """Create and configure the FastAPI application.
+
+    Args:
+        config: Configuration instance
+
+    Returns:
+        Configured FastAPI app
+    """
+    config = config or Config()
+
+    app = FastAPI(
+        title="X-Agents API",
+        description="Agent API for X-Agents platform",
+        version="0.1.0",
+    )
+
+    # Include routers with /api/v1 prefix (aligned with Go backend paths: /api/agent/chat, /api/agent/chat/stream)
+    app.include_router(router, prefix="/api/v1")
+
+    # Add CORS middleware to allow Go backend cross-origin requests
+    add_cors(app)
+
+    # Initialize LLM provider
+    if config.LLM_API_KEY:
+        try:
+            provider = ProviderFactory.create(
+                provider=config.LLM_PROVIDER,
+                api_key=config.LLM_API_KEY,
+                api_base=config.LLM_BASE_URL,
+            )
+            logger.info(f"Using {config.LLM_PROVIDER} provider with model {config.LLM_MODEL}")
+        except ImportError as e:
+            logger.warning(f"Failed to import provider package: {e}, using placeholder")
+            provider = SimpleProvider(api_key=config.LLM_API_KEY)
+    else:
+        logger.warning("No LLM_API_KEY provided, using placeholder provider")
+        provider = SimpleProvider()
+
+    # Create tool registry
+    tools = create_default_registry()
+
+    # Initialize agent
+    agent = AgentLoop(
+        provider=provider,
+        model=config.LLM_MODEL,
+        workspace=config.WORKSPACE,
+        max_iterations=config.MAX_ITERATIONS,
+        tools=tools,
+    )
+
+    set_agent(agent)
+
+    # Initialize team agent for multi-agent collaboration
+    team_agent = TeamAgent(
+        provider=provider,
+        model=config.LLM_MODEL,
+        workspace=config.WORKSPACE,
+    )
+    set_team_agent(team_agent)
+
+    @app.on_event("startup")
+    async def startup_event():
+        logger.info("X-Agents starting up...")
+        logger.info(f"Model: {config.LLM_MODEL}")
+        logger.info(f"Provider: {config.LLM_PROVIDER}")
+        logger.info(f"Workspace: {config.WORKSPACE}")
+        logger.info(f"Tools: {tools.tool_names}")
+
+    @app.on_event("shutdown")
+    async def shutdown_event():
+        logger.info("X-Agents shutting down...")
+
+    return app
+
+
+def main():
+    """Run the agent service."""
+    config = Config()
+
+    # Ensure workspace exists
+    config.WORKSPACE.mkdir(exist_ok=True)
+
+    app = create_app(config)
+
+    uvicorn.run(
+        app,
+        host=config.API_HOST,
+        port=config.API_PORT,
+        log_level="info",
+    )
+
+
+if __name__ == "__main__":
+    main()