Editor opens in native windows (one per file)

Real BrowserWindow per edited file with its own RPC instance, deduped by
sessionId+path. The same Angular bundle boots an editor-only root via
preload globals. Native close isn't cancellable in electrobun, so the
editor mirrors its draft to bun; traffic-light closes get a native
Save/Discard prompt after the fact, and failed saves park the draft in
the edit-leftovers dir. In-window closes (Cmd+W, Close) use a styled
prompt; the quit guard now also counts unsaved editors.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

ui/src/app/app.ts

@@ -5,7 +5,6 @@ import { ConnectionManager } from './connection-manager/connection-manager';
 import { ConnectionsService } from './connections.service';
 import { ChmodDialog } from './dialogs/chmod-dialog';
 import { ConfirmDialog } from './dialogs/confirm-dialog';
-import { EditorDialog } from './dialogs/editor-dialog';
 import { OverwriteDialog } from './dialogs/overwrite-dialog';
 import { PromptDialog } from './dialogs/prompt-dialog';
 import { DialogsService } from './dialogs.service';
@@ -16,6 +15,7 @@ import { RpcService } from './rpc.service';
 import { StatusBar } from './status-bar/status-bar';
 import { TabBar } from './tab-bar/tab-bar';
 import { ToastService } from './toast.service';
+import { Toasts } from './toasts/toasts';
 import { TransferBar } from './transfer-bar/transfer-bar';
 import { TransfersService } from './transfers.service';
 
@@ -30,7 +30,7 @@ import { TransfersService } from './transfers.service';
     ConfirmDialog,
     ChmodDialog,
     OverwriteDialog,
-    EditorDialog,
+    Toasts,
     TransferBar,
     ConnectionManager,
   ],
@@ -174,9 +174,4 @@ export class App {
     }
   }
 
-  toastIcon(kind: 'error' | 'info' | 'success'): string {
-    if (kind === 'error') return 'mynaXCircle';
-    if (kind === 'success') return 'mynaCheckCircle';
-    return 'mynaCheck';
-  }
 }