fix(desktop): session persistence — refresh/login/context/empty-content 4-bug fix

1. App.tsx: add restoreSession() call on startup to prevent redirect
   to login page after refresh (isRestoring guard + BootstrapScreen)
2. CloneManager: call syncAgents() after loadClones() to restore
   currentAgent and conversation history on app load
3. zclaw-memory: add get_or_create_session() so frontend session UUID
   is persisted directly — kernel no longer creates mismatched IDs
4. openai.rs: assistant message content must be non-empty for
   Kimi/Qwen APIs — replace empty content with meaningful placeholders

Also includes admin-v2 ModelServices unified page (merge providers +
models + API keys into expandable row layout)

admin-v2/package.json

@@ -25,6 +25,7 @@
   },
   "devDependencies": {
     "@eslint/js": "^9.39.4",
+    "@tailwindcss/vite": "^4.2.2",
     "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/react": "^16.3.2",
     "@testing-library/user-event": "^14.6.1",
@@ -38,6 +39,7 @@
     "globals": "^17.4.0",
     "jsdom": "^29.0.1",
     "msw": "^2.12.14",
+    "tailwindcss": "^4.2.2",
     "typescript": "~5.9.3",
     "typescript-eslint": "^8.57.0",
     "vite": "^8.0.1",