fix: #33 内置多模态工具现在在工具市场 /api/v1/tools 中可见

list_tools 端点合并内置工具（image_ocr/image_vision/speech_to_text/text_to_speech 等），
按 scope=public/all 时自动包含，无需额外种子到 DB。

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

backend/app/api/tools.py

@@ -96,6 +96,44 @@ def _tool_to_dict(tool: Tool) -> dict:
 # ─── 工具市场浏览 ──────────────────────────────────────────────
 
 
+def _builtin_schema_to_tool_dict(schema: dict) -> dict:
+    """将 tool_registry 中的 schema 转为与 DB Tool 一致的字典格式。"""
+    func = schema.get("function", schema)
+    name = func.get("name", "")
+    desc = func.get("description", "")
+    params = func.get("parameters", {})
+    # 根据工具名自动归类
+    cat = "系统工具"
+    if name in ("image_ocr", "image_vision"):
+        cat = "多模态"
+    elif name in ("speech_to_text", "text_to_speech"):
+        cat = "多模态"
+    elif name.startswith("file_"):
+        cat = "文件操作"
+    elif name.startswith("http") or name.startswith("url"):
+        cat = "网络请求"
+    elif name.startswith("database") or name.startswith("sql"):
+        cat = "数据库"
+    elif name.startswith("agent_"):
+        cat = "AI Agent"
+    elif name in ("web_search", "send_email", "browser_use"):
+        cat = "网络请求"
+    return {
+        "id": f"builtin_{name}",
+        "name": name,
+        "description": desc,
+        "category": cat,
+        "function_schema": schema,
+        "implementation_type": "builtin",
+        "implementation_config": None,
+        "is_public": True,
+        "use_count": 0,
+        "user_id": None,
+        "created_at": "",
+        "updated_at": "",
+    }
+
+
 @router.get("", response_model=List[ToolResponse])
 async def list_tools(
     category: Optional[str] = Query(None, description="按分类筛选"),
@@ -104,7 +142,7 @@ async def list_tools(
     db: Session = Depends(get_db),
     current_user: Optional[User] = Depends(get_current_user),
 ):
-    """浏览工具市场。"""
+    """浏览工具市场（含内置工具 + 数据库工具）。"""
     query = db.query(Tool)
 
     if scope == "public":
@@ -122,7 +160,23 @@ async def list_tools(
         )
 
     tools = query.order_by(Tool.use_count.desc(), Tool.created_at.desc()).all()
-    return [_tool_to_dict(t) for t in tools]
+    result = [_tool_to_dict(t) for t in tools]
+    db_names = {t["name"] for t in result}
+
+    # 合并内置工具（未在 DB 中覆盖的）
+    if scope != "mine":
+        for schema in tool_registry.get_all_tool_schemas():
+            entry = _builtin_schema_to_tool_dict(schema)
+            if entry["name"] not in db_names:
+                if category and entry["category"] != category:
+                    continue
+                if search:
+                    kw = search.lower()
+                    if kw not in entry["name"].lower() and kw not in entry["description"].lower():
+                        continue
+                result.append(entry)
+
+    return result
 
 
 @router.get("/categories", response_model=List[str])
@@ -131,7 +185,7 @@ async def list_categories(db: Session = Depends(get_db)):
     rows = db.query(Tool.category).filter(Tool.category.isnot(None)).distinct().all()
     cats = sorted(set(r[0] for r in rows if r[0]))
     # 加上常用分类
-    defaults = ["数据处理", "网络请求", "文件操作", "AI服务", "数据库", "通知", "自定义"]
+    defaults = ["数据处理", "网络请求", "文件操作", "AI服务", "数据库", "通知", "自定义", "多模态", "系统工具"]
     for d in defaults:
         if d not in cats:
             cats.append(d)