新增前后端AI聊天模块，包括流式对话、配置管理和UI组件优化。

backend/app/routers/ai_config.py

@@ -0,0 +1,99 @@
+from datetime import datetime, timezone
+
+import httpx
+from fastapi import APIRouter, Depends
+from sqlmodel import Session, select
+
+from ..database import get_session
+from ..models import AIConfig
+from ..schemas import AIConfigSave, AIConfigRead
+
+router = APIRouter(prefix="/api/ai", tags=["ai-config"])
+
+
+def _mask_key(key: str) -> str:
+    if len(key) <= 8:
+        return "****"
+    return key[:4] + "****" + key[-4:]
+
+
+def _get_or_create_config(session: Session) -> AIConfig:
+    config = session.exec(select(AIConfig)).first()
+    if not config:
+        config = AIConfig()
+        session.add(config)
+        session.commit()
+        session.refresh(config)
+    return config
+
+
+def _config_to_read(config: AIConfig) -> AIConfigRead:
+    return AIConfigRead(
+        id=config.id,
+        provider=config.provider,
+        base_url=config.base_url,
+        api_key_masked=_mask_key(config.api_key) if config.api_key else "",
+        model=config.model,
+        updated_at=config.updated_at,
+    )
+
+
+@router.get("/config", response_model=AIConfigRead)
+def get_config(session: Session = Depends(get_session)):
+    config = _get_or_create_config(session)
+    return _config_to_read(config)
+
+
+@router.put("/config", response_model=AIConfigRead)
+def save_config(data: AIConfigSave, session: Session = Depends(get_session)):
+    config = _get_or_create_config(session)
+    config.provider = data.provider
+    config.base_url = data.base_url
+    config.api_key = data.api_key
+    config.model = data.model
+    config.updated_at = datetime.now(timezone.utc)
+    session.add(config)
+    session.commit()
+    session.refresh(config)
+    return _config_to_read(config)
+
+
+@router.post("/config/test")
+async def test_config(data: AIConfigSave):
+    """测试AI连接是否有效"""
+    try:
+        async with httpx.AsyncClient(timeout=15) as client:
+            if data.provider == "anthropic":
+                resp = await client.post(
+                    f"{data.base_url.rstrip('/')}/messages",
+                    headers={
+                        "x-api-key": data.api_key,
+                        "anthropic-version": "2023-06-01",
+                        "content-type": "application/json",
+                    },
+                    json={
+                        "model": data.model,
+                        "max_tokens": 10,
+                        "messages": [{"role": "user", "content": "Hi"}],
+                    },
+                )
+            else:
+                resp = await client.post(
+                    f"{data.base_url.rstrip('/')}/chat/completions",
+                    headers={
+                        "Authorization": f"Bearer {data.api_key}",
+                        "Content-Type": "application/json",
+                    },
+                    json={
+                        "model": data.model,
+                        "max_tokens": 10,
+                        "messages": [{"role": "user", "content": "Hi"}],
+                    },
+                )
+            if resp.status_code < 400:
+                return {"ok": True, "message": "连接成功"}
+            return {"ok": False, "message": f"API返回错误: {resp.status_code}"}
+    except httpx.ConnectError:
+        return {"ok": False, "message": "无法连接到API地址"}
+    except Exception as e:
+        return {"ok": False, "message": str(e)}