Strip whitespace from endpoint URLs before use

Leading/trailing spaces in the endpoint field cause httpx to receive
a URL without a recognisable scheme, producing UnsupportedProtocol.

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

server.py

@@ -280,7 +280,7 @@ async def handle_agent0_mcp(
     from mcp.client.streamable_http import streamablehttp_client
     from mcp import ClientSession
 
-    endpoint = (model.endpoint or "").rstrip("/")
+    endpoint = (model.endpoint or "").strip().rstrip("/")
     mcp_key  = model.mcp_key or ""
     mcp_url  = f"{endpoint}/mcp/t-{mcp_key}/http"
 
@@ -405,7 +405,7 @@ async def handle_hermes(
     except ImportError:
         from websockets.client import connect as ws_connect  # type: ignore
 
-    endpoint  = (model.endpoint or "").rstrip("/")
+    endpoint  = (model.endpoint or "").strip().rstrip("/")
     hermes_session_id = _hermes_sessions.get(req.conversation_id) if req.conversation_id else None
 
     token = await _fetch_hermes_token(endpoint)