v1.3.1

fix: MiMo API, thinking display, mobile API routes, auto-update - v1.3.1

Fixes:
- MiMo: remove conflicting 'thinking' field, explicitly set webSearchEnabled=false
- Desktop thinking: stop stripping think blocks before renderMessageContent
- Mobile API: add missing routes (test-provider, discover, delete agent/memory,
  skills install/refresh, codegen streaming)
- Mobile apiAdapter: add /api/codegen to streaming paths

Features:
- Auto-update checker (UpdateChecker component for desktop + mobile)
- Checks GitHub releases, shows download banner with platform-specific asset
- updater.ts: version comparison + platform asset detection
- Codegen streaming support for mobile via handleCodeGenStream

Version: 1.3.0 -> 1.3.1