fix(plugins): skip modal teardown for stale plugin panel closes

handleModalClosed now reports whether teardown should continue. A late
close notice for a replaced panel returns before the generic modal-close
flow, so it no longer hides the modal window showing the newer panel.

src/main.ts

@@ -6040,12 +6040,17 @@ const { registerIpcRuntimeHandlers } = composeIpcRuntimeHandlers({
         }
       },
       onOverlayModalClosed: (modal, senderWindow, instanceId) => {
+        // A late close for a replaced plugin panel must not hide the panel now showing.
+        if (
+          modal === 'plugin-panel' &&
+          instanceId !== undefined &&
+          !pluginPanelRuntime.handleModalClosed(instanceId)
+        ) {
+          return;
+        }
         if (modal === 'media-timing-review') {
           void mediaTimingReviewRuntime.dispose();
         }
-        if (modal === 'plugin-panel' && instanceId !== undefined) {
-          pluginPanelRuntime.handleModalClosed(instanceId);
-        }
         if (modal === 'subtitle-sidebar' && senderWindow === overlayManager.getMainWindow()) {
           subtitleSidebarRequestedOpen = false;
         }

src/main/runtime/plugin-panel-runtime.test.ts

@@ -44,7 +44,7 @@ test('closing from the overlay aborts the handle and ignores later updates', asy
   await new Promise((resolve) => setImmediate(resolve));
   const sentBefore = h.sent.length;
 
-  h.runtime.handleModalClosed(1);
+  assert.equal(h.runtime.handleModalClosed(1), true);
   panel.update({ markdown: 'too late' });
 
   assert.equal(panel.signal.aborted, true);
@@ -58,11 +58,17 @@ test('a late close acknowledgement for a replaced panel leaves the new panel ope
   first.close();
   const second = h.runtime.open({ title: 'Two', markdown: '' });
 
-  h.runtime.handleModalClosed(1);
-
+  assert.equal(h.runtime.handleModalClosed(1), false, 'skip teardown of the newer panel');
   assert.equal(second.signal.aborted, false);
 });
 
+test('a close notice after the plugin closed its panel still tears the modal down', () => {
+  const h = createHarness(Promise.resolve(true));
+  h.runtime.open({ title: 'One', markdown: '' }).close();
+
+  assert.equal(h.runtime.handleModalClosed(1), true);
+});
+
 test('opening a new panel aborts the previous one', () => {
   const h = createHarness(Promise.resolve(true));
   const first = h.runtime.open({ title: 'One', markdown: '' });

src/main/runtime/plugin-panel-runtime.ts

@@ -103,9 +103,15 @@ export function createPluginPanelRuntime(deps: {
       };
     },
 
-    /** The overlay closed `panelId`; a late notice for an already replaced panel is ignored. */
-    handleModalClosed(panelId: number): void {
-      if (active?.panelId === panelId) finish(active);
+    /**
+     * The overlay closed `panelId`. Returns false for a late notice about a panel that a newer one
+     * already replaced, so the caller skips the modal teardown that would hide the newer panel.
+     */
+    handleModalClosed(panelId: number): boolean {
+      if (!active) return true;
+      if (active.panelId !== panelId) return false;
+      finish(active);
+      return true;
     },
   };
 }