Tauri IPC commands fail silently when testing via browser at localhost. Use when:
(1) Tauri invoke() calls return no data or fail silently in Playwright/browser tests,
(2) window.__TAURI__ is undefined when accessing localhost:port directly,
(3) App works in Tauri window but not when tested via browser automation,
(4) React Query or other data fetching shows empty results for Tauri commands.
The fix is to test in the actual Tauri webview or mock the Tauri API for browser tests.