feat: backend servis iskeletini ve yönetim uçlarını ekle

backend/app/tools/web_fetch.py

@@ -0,0 +1,18 @@
+from typing import Any
+
+from app.tools.base import Tool
+
+
+class WebFetchTool(Tool):
+    name = "web_fetch"
+    description = "Fetch a webpage and return simplified content."
+
+    async def run(self, payload: dict[str, Any]) -> dict[str, Any]:
+        url = str(payload.get("url", "")).strip()
+        return {
+            "tool": self.name,
+            "status": "stub",
+            "url": url,
+            "message": "Web fetch integration is not wired yet.",
+        }
+