Handle hotfix upgrade messaging and clear stale update state after applying updates.
- UpdateController: when notifying admins for hotfixes, pass the current app version as the "to" version so notifications read e.g. "v1.1.3 has been updated" instead of showing a commit SHA.
- NotificationService: adjust system upgrade message to show a simple "has been updated" message when fromVersion equals toVersion (hotfix/file updates) and standard "upgraded from X to Y" otherwise; factor migration label formatting.
- UpdateService: clear cached update-check state after a successful update (add clearUpdateCache method) so the UI no longer shows a stale "update available" card. Keep latest_available_version unchanged to avoid view inconsistencies before migrations run.
Installer: capture the current app version (fromVersion) before running migrations, with a fallback for very old installs where settings may not exist. Re-read the app version after migrations to determine toVersion and only use migration-based detection as a fallback when the version didn't change.
Update flow: only send admin upgrade notifications when there are no pending migrations. If migrations remain, the user is redirected to the installer which will send the correct notification after migrations complete. This prevents duplicate or incorrect upgrade notifications and ensures accurate from/to version reporting.
Implement CSV/JSON import and export for domains, notification groups and tags (with masking for sensitive channel data), including size/format validation, in-memory CSV building, and logging. Add tag transfer and bulk transfer actions (admin-only). Introduce a new update system: Add UpdateController and UpdateService, migration 025_add_update_system_v1.1.3.sql, and installer changes to include the new migration and version handling; provide endpoints to check, apply, rollback and configure updates. Update helpers and UI bits: add getUpdateBadgeInfo in LayoutHelper, update notification icons/redirects, and add getMaxUploadSize in ViewHelper. Misc: add NotificationGroup::findByName, tweak .gitignore backups path, and update related views and routes.
