fix(tray): drop "Welcome back" toast on tray-icon restore

Restoring from the tray popped a "Welcome back" toast every time — noise for
a routine action. Removed it from onTrayRestore; the auto-lock reset stays.
The login-success "Welcome back, <user>" toast is unaffected.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

js/app.js

@@ -101,7 +101,6 @@ const Bridge = (() => {
             // unlocked.
             if (state.cryptoKey && !state.locked) {
                 if (typeof resetAutoLock === 'function') resetAutoLock();
-                if (typeof toast === 'function') toast('Welcome back');
             }
         },