Fix uuid dependency and silent error swallowing FRE-4572

- Replace uuid package with expo-crypto randomUUID (already a dependency)
- Add error logging to darkWatchStore refreshExposures catch block
- TypeScript compiles clean

packages/mobile/src/store/darkWatchStore.ts

@@ -1,7 +1,7 @@
 import { create } from 'zustand';
 import { persist, createJSONStorage } from 'zustand/middleware';
 import AsyncStorage from '@react-native-async-storage/async-storage';
-import { v4 as uuidv4 } from 'uuid';
+import { randomUUID } from 'expo-crypto';
 import type { WatchListItem, Exposure } from '@/types';
 
 /**
@@ -29,7 +29,7 @@ export const useDarkWatchStore = create<DarkWatchState>()(
       addWatchItem: async (item) => {
         const newItem: WatchListItem = {
           ...item,
-          id: uuidv4(),
+          id: randomUUID(),
           lastChecked: new Date().toISOString(),
         };
         set((state) => ({ watchList: [...state.watchList, newItem] }));
@@ -52,8 +52,10 @@ export const useDarkWatchStore = create<DarkWatchState>()(
       refreshExposures: async () => {
         set({ isLoading: true });
         try {
+          // TODO: Wire to @shieldai/mobile-api-client for production
           set({ isLoading: false });
-        } catch {
+        } catch (error) {
+          console.error('[DarkWatch] Failed to refresh exposures:', error);
           set({ isLoading: false });
         }
       },

packages/mobile/src/store/voicePrintStore.ts

@@ -1,7 +1,7 @@
 import { create } from 'zustand';
 import { persist, createJSONStorage } from 'zustand/middleware';
 import AsyncStorage from '@react-native-async-storage/async-storage';
-import { v4 as uuidv4 } from 'uuid';
+import { randomUUID } from 'expo-crypto';
 import type { VoiceProfile, VoiceAnalysis } from '@/types';
 
 /**
@@ -30,7 +30,7 @@ export const useVoicePrintStore = create<VoicePrintState>()(
 
       addProfile: async (name: string, relationship: string) => {
         const newProfile: VoiceProfile = {
-          id: uuidv4(),
+          id: randomUUID(),
           name,
           relationship,
           enrolledAt: new Date().toISOString(),