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/providers/openai_provider.py

@@ -0,0 +1,150 @@
+"""OpenAI LLM provider implementation."""
+
+import json
+import secrets
+import string
+from typing import Any
+
+import aiohttp
+from loguru import logger
+
+from agents.providers.base import LLMProvider, LLMResponse, ToolCallRequest
+
+_ALNUM = string.ascii_letters + string.digits
+
+
+def _short_tool_id() -> str:
+    """Generate a 9-char alphanumeric ID for tool calls."""
+    return "".join(secrets.choice(_ALNUM) for _ in range(9))
+
+
+class OpenAIProvider(LLMProvider):
+    """OpenAI LLM provider using OpenAI API."""
+
+    def __init__(
+        self,
+        api_key: str | None = None,
+        api_base: str | None = None,
+        default_model: str = "gpt-4o",
+    ):
+        super().__init__(api_key, api_base)
+        self.default_model = default_model
+        self._session: aiohttp.ClientSession | None = None
+
+    async def _get_session(self) -> aiohttp.ClientSession:
+        """Get or create aiohttp session."""
+        if self._session is None or self._session.closed:
+            self._session = aiohttp.ClientSession()
+        return self._session
+
+    async def close(self):
+        """Close the HTTP session."""
+        if self._session and not self._session.closed:
+            await self._session.close()
+
+    async def chat(
+        self,
+        messages: list[dict[str, Any]],
+        tools: list[dict[str, Any]] | None = None,
+        model: str | None = None,
+        max_tokens: int = 4096,
+        temperature: float = 0.7,
+    ) -> LLMResponse:
+        """Send a chat completion request to OpenAI API."""
+        model = model or self.default_model
+        api_base = self.api_base or "https://api.openai.com/v1"
+        url = f"{api_base}/chat/completions"
+
+        headers = {
+            "Content-Type": "application/json",
+        }
+        if self.api_key:
+            headers["Authorization"] = f"Bearer {self.api_key}"
+
+        # Sanitize messages
+        messages = self._sanitize_empty_content(messages)
+
+        payload: dict[str, Any] = {
+            "model": model,
+            "messages": messages,
+            "max_tokens": max_tokens,
+            "temperature": temperature,
+        }
+
+        if tools:
+            payload["tools"] = tools
+            payload["tool_choice"] = "auto"
+
+        try:
+            session = await self._get_session()
+            async with session.post(url, json=payload, headers=headers) as resp:
+                if resp.status != 200:
+                    error_text = await resp.text()
+                    return LLMResponse(
+                        content=f"OpenAI API error (status {resp.status}): {error_text}",
+                        finish_reason="error",
+                    )
+
+                data = await resp.json()
+                return self._parse_response(data)
+
+        except aiohttp.ClientError as e:
+            return LLMResponse(
+                content=f"OpenAI API connection error: {str(e)}",
+                finish_reason="error",
+            )
+        except Exception as e:
+            return LLMResponse(
+                content=f"Error calling OpenAI: {str(e)}",
+                finish_reason="error",
+            )
+
+    def _parse_response(self, data: dict[str, Any]) -> LLMResponse:
+        """Parse OpenAI API response into our standard format."""
+        choices = data.get("choices", [])
+        if not choices:
+            return LLMResponse(content="", finish_reason="stop")
+
+        choice = choices[0]
+        message = choice.get("message", {})
+        content = message.get("content")
+        finish_reason = choice.get("finish_reason", "stop")
+
+        # Parse tool calls
+        tool_calls = []
+        raw_tool_calls = message.get("tool_calls", [])
+        for tc in raw_tool_calls:
+            func = tc.get("function", {})
+            args_str = func.get("arguments", "{}")
+            if isinstance(args_str, str):
+                try:
+                    args = json.loads(args_str)
+                except json.JSONDecodeError:
+                    args = {}
+            else:
+                args = args_str
+
+            tool_calls.append(ToolCallRequest(
+                id=tc.get("id", _short_tool_id()),
+                name=func.get("name", ""),
+                arguments=args,
+            ))
+
+        # Parse usage
+        usage = data.get("usage", {})
+        usage_dict = {
+            "prompt_tokens": usage.get("prompt_tokens", 0),
+            "completion_tokens": usage.get("completion_tokens", 0),
+            "total_tokens": usage.get("total_tokens", 0),
+        }
+
+        return LLMResponse(
+            content=content,
+            tool_calls=tool_calls,
+            finish_reason=finish_reason,
+            usage=usage_dict,
+        )
+
+    def get_default_model(self) -> str:
+        """Get the default model."""
+        return self.default_model