- Add Integration interfaces, registry, cache, encryption, and base helpers
- Add integrationType, integrationConfig, integrationEnabled to App model
- Add integration widget type to constants and validators
- Add integration fields to AppRecord, CreateAppInput, UpdateAppInput
- Update appService with encryption/decryption for integration config
- Add API routes: list integrations, test connection, fetch endpoint data
- JSON import/export with conflict resolution (skip/overwrite) + admin UI
- Ping history sparklines on AppWidget and AppCard (24h, 288 points)
- Hourly cleanup job for old AppStatus records
- User theme preferences (hue, saturation, mode, background, locale)
- Settings page with ThemeCustomizer (sliders, toggles, live preview)
- Prisma migration for user preference fields
- i18n translations for all new strings (EN/RU)