Migrate monorepo to Zod 4

packages/app/package.json

@@ -109,7 +109,7 @@
     "react-native-worklets": "~0.8.3",
     "tiny-invariant": "^1.3.3",
     "use-sync-external-store": "^1.6.0",
-    "zod": "^3.23.8",
+    "zod": "^4.4.3",
     "zustand": "^5.0.9"
   },
   "devDependencies": {

packages/app/src/create-agent-preferences/preferences.ts

@@ -18,13 +18,13 @@ export interface FavoriteModelRow {
 const providerPreferencesSchema = z.object({
   model: z.string().optional(),
   mode: z.string().optional(),
-  thinkingByModel: z.record(z.string()).optional(),
-  featureValues: z.record(z.unknown()).optional(),
+  thinkingByModel: z.record(z.string(), z.string()).optional(),
+  featureValues: z.record(z.string(), z.unknown()).optional(),
 });
 
 const formPreferencesSchema = z.object({
   provider: z.string().optional(),
-  providerPreferences: z.record(providerPreferencesSchema).optional(),
+  providerPreferences: z.record(z.string(), providerPreferencesSchema).optional(),
   favoriteModels: z
     .array(
       z.object({