fix(plugins): ignore stale plugin panel close notices

The overlay's modal-closed notice now carries the panel id, and the
runtime only finishes the active panel when the ids match. A late notice
for a replaced panel no longer aborts the newer one.

src/types/runtime.ts

@@ -625,6 +625,8 @@ export interface ElectronAPI {
       | 'character-dictionary'
       | 'changelog'
       | 'plugin-panel',
+    /** Which instance closed, for modals that swap content in place (the plugin panel's id). */
+    instanceId?: number,
   ) => void;
   notifyOverlayModalOpened: (
     modal: