feat(exec): add path prepend config

webui/src/lib/types.ts

@@ -480,6 +480,7 @@ export interface SettingsPayload {
     mcp_server_count: number;
     exec_enabled: boolean;
     exec_sandbox?: string | null;
+    exec_path_prepend_set: boolean;
     exec_path_append_set: boolean;
   };
   requires_restart: boolean;