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/panels.service.ts

@@ -223,6 +223,13 @@ export class PanelsService {
         }
       }
     });
+
+    // an editor window saved a file — refresh panels showing that directory
+    this.rpc.onPathRefresh(({ sessionId, dir }) => {
+      for (const panel of this.allPanels()) {
+        if (panel.sessionId() === sessionId && panel.cwd() === dir) void panel.refresh();
+      }
+    });
   }
 
   // ---- panels of the active workspace ----