fix(npcs): stop TipTap crash black screen in secondary windows

Guard TipTap getHTML under StrictMode, wrap secondary window roots in WindowErrorBoundary, and add stability regression tests.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/renderer/npcs/NpcsEditorApp.tsx

@@ -19,6 +19,7 @@ import { Button, Input, Select } from '../shared/ui/controls';
 import { useAssetUrl } from '../shared/useAssetImageUrl';
 
 import { NpcBindingFields } from './NpcBindingFields';
+import { NpcDescriptionField } from './NpcDescriptionField';
 import { NpcEditModal } from './NpcEditModal';
 import type { GraphGroupFilter } from './NpcGraph';
 import { NpcGroupModal } from './NpcGroupModal';
@@ -36,11 +37,6 @@ const NpcGraph = lazy(async () => {
   return { default: mod.NpcGraph };
 });
 
-const NpcDescriptionField = lazy(async () => {
-  const mod = await import('./NpcDescriptionField');
-  return { default: mod.NpcDescriptionField };
-});
-
 const DND_NPC_ID_MIME = 'application/x-dnd-npc-id';
 const DND_NPC_GROUP_ID_MIME = 'application/x-dnd-npc-group-id';
 
@@ -813,18 +809,17 @@ export function NpcsEditorApp() {
 
                 <div>
                   <div className={styles.fieldLabel}>{t('npcs.description')}</div>
-                  <Suspense fallback={<div className={styles.muted}>{t('npcs.savingWait')}</div>}>
-                    <NpcDescriptionField
-                      html={selected.description}
-                      onCommit={(html) => {
-                        if (html === selected.description) return;
-                        void api.invoke(ipcChannels.project.updateNpcFields, {
-                          npcId: selected.id,
-                          description: html,
-                        });
-                      }}
-                    />
-                  </Suspense>
+                  <NpcDescriptionField
+                    key={selected.id}
+                    html={selected.description}
+                    onCommit={(html) => {
+                      if (html === selected.description) return;
+                      void api.invoke(ipcChannels.project.updateNpcFields, {
+                        npcId: selected.id,
+                        description: html,
+                      });
+                    }}
+                  />
                 </div>
 
                 <div>