Update streamable_http_path to /mcp/ to avoid 307 Temporary Redirect

Author: chi2liu

src/mcp/server/fastmcp/server.py

@@ -92,7 +92,7 @@ class Settings(BaseSettings, Generic[LifespanResultT]):
     mount_path: str = "/"  # Mount path (e.g. "/github", defaults to root path)
     sse_path: str = "/sse"
     message_path: str = "/messages/"
-    streamable_http_path: str = "/mcp"
+    streamable_http_path: str = "/mcp/"
 
     # StreamableHTTP settings
     json_response: bool = False