Mobile: Offline support and network monitoring

[krusty-agent]

Overview

Implements native offline support for the mobile app using Capacitor's Network plugin.

Changes

• @capacitor/network plugin for native network status monitoring
• Network service (src/lib/network.ts) that provides:
  • Unified API for network status across web and native platforms
  • Web fallback using navigator.onLine
  • Native network monitoring via @capacitor/network
• Updated useOffline hook to use the new network service instead of browser-only events
• Initialization of network monitoring in main.tsx

Testing

• ✅ Build passes (npm run build)
• Uses existing OfflineIndicator component for UI feedback
• Auto-triggers sync when connection is restored

Notes

• Works seamlessly with the existing offline/sync infrastructure
• PR fix: Add Capacitor compatibility fixes for mobile apps #70 handles service worker disabling on native platforms
• This PR provides proper native network detection for Capacitor apps