feat: add app upgrade system with self-hosted APK update support
- Add core/updater module: version checker, download manager (resumable + SHA-256),
APK installer, app market detector, self-hosted updater with progress dialogs
- Add Android native MethodChannels for APK installation and market detection
- Add FileProvider config and REQUEST_INSTALL_PACKAGES permission
- Wire UpdateService singleton into main.dart initialization
- Add auto-check on home entry with cooldown + app resume detection
- Add manual "检查更新" button and dynamic version display in settings
- Fix chat page: bottom overflow, bash spinner persistence, collapsible results
- Merge standing orders into tasks page as second tab
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
hailin
f5d9b1f04f