The dev build was missing a capabilities/default.json so the
event:listen and notification:is-permission-granted plugins
denied every IPC call from main.ts (logged as 'event.listen not
allowed' etc. in DevTools). Add the minimum set needed by
client.ts / main.ts and the AppView/Tauri commands registered
in lib.rs.
Also open the webview devtools automatically on startup behind
a debug_assertions guard, so the frontend console + DOM inspector
are available without reaching for the macOS View menu.
