feat(npcs): add campaign NPCs with relation graph and session overlay

Add a dedicated NPC editor window, directed relations, control/presentation avatar overlay, and ru/en help for the new section.

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

app/renderer/npcs/npcsEditorMain.tsx

@@ -0,0 +1,20 @@
+import React from 'react';
+import { createRoot } from 'react-dom/client';
+
+import '../shared/ui/globals.css';
+import { EditorI18nProvider } from '../editor/i18n/EditorI18nContext';
+
+import { NpcsEditorApp } from './NpcsEditorApp';
+
+const rootEl = document.getElementById('root');
+if (!rootEl) {
+  throw new Error('Missing #root element');
+}
+
+createRoot(rootEl).render(
+  <React.StrictMode>
+    <EditorI18nProvider>
+      <NpcsEditorApp />
+    </EditorI18nProvider>
+  </React.StrictMode>,
+);