feat: add AntafLLM provider for Ant Afu text API integration

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/main/xiaozhi-server/core/providers/llm/antaf/antaf.py

@@ -0,0 +1,66 @@
+import requests
+from config.logger import setup_logging
+from core.providers.llm.base import LLMProviderBase
+
+TAG = __name__
+logger = setup_logging()
+
+
+class LLMProvider(LLMProviderBase):
+    """
+    蚂蚁阿福 LLM Provider
+    通过 Frida HTTP Bridge (port 18900) 对接蚂蚁阿福 App 的文字对话 API。
+    Bridge 运行在手机上，通过 adb forward 或网络暴露 SSE 流式接口。
+    """
+
+    def __init__(self, config):
+        self.bridge_url = config.get("bridge_url", "http://127.0.0.1:18900")
+        self.timeout = config.get("timeout", 60)
+        logger.bind(tag=TAG).info(
+            f"AntafLLM 初始化: bridge={self.bridge_url}, timeout={self.timeout}s"
+        )
+
+    def response(self, session_id, dialogue, **kwargs):
+        # 提取最后一条用户消息
+        query = ""
+        for msg in reversed(dialogue):
+            if msg.get("role") == "user":
+                query = msg.get("content", "")
+                break
+
+        if not query:
+            logger.bind(tag=TAG).warning("对话中没有用户消息")
+            yield "抱歉，我没有收到您的问题。"
+            return
+
+        logger.bind(tag=TAG).info(f"AntafLLM 请求: {query[:50]}...")
+
+        try:
+            url = f"{self.bridge_url}/chat"
+            resp = requests.get(
+                url,
+                params={"q": query},
+                stream=True,
+                timeout=self.timeout,
+            )
+            resp.encoding = "utf-8"
+
+            for line in resp.iter_lines(decode_unicode=True):
+                if not line:
+                    continue
+                if line.startswith("data: "):
+                    data = line[6:]
+                    if data == "[DONE]":
+                        break
+                    if data and len(data.strip()) > 0:
+                        yield data
+
+        except requests.exceptions.ConnectionError:
+            logger.bind(tag=TAG).error("无法连接蚂蚁阿福 Bridge，请检查手机和 Frida 状态")
+            yield "抱歉，蚂蚁阿福服务暂时不可用。"
+        except requests.exceptions.Timeout:
+            logger.bind(tag=TAG).error(f"蚂蚁阿福 Bridge 超时 ({self.timeout}s)")
+            yield "抱歉，回答超时了。"
+        except Exception as e:
+            logger.bind(tag=TAG).error(f"AntafLLM 异常: {e}")
+            yield "抱歉，发生了错误。"