frontend: add electron service bootstrap, preload and api client

FE-001: detect and launch the local mactfs-server, expose a narrow preload
bridge (token, service status, directory picker), and add a unified API
client that auto-attaches the Bearer token. Home becomes a bootstrap gate
with a retry entry. Update task board, FE-001 record and FRONTEND_SPEC.

Co-authored-by: Cursor <cursoragent@cursor.com>

mactfsui/app/lib/api/index.ts

@@ -0,0 +1,2 @@
+export type { ApiRequestOptions, ApiResponse, ApiResult } from "./types"
+export { apiClient } from "./client"