Replace per-device CheckMK URL field with a global, IP-based lookup.
The sync job fetches all host configs from CheckMK once per cycle,
matches each device by IP address, and updates its status accordingly.
Devices not found in CheckMK are reset to 'unknown'.
- Add checkmk_enabled / checkmk_api_user settings; toggle in Settings
mirrors the Entra ID pattern (fields dim when disabled)
- Sync job uses self-scheduling setTimeout so interval changes apply
without a server restart; POST /api/checkmk/sync for manual triggers
- Status changes and a per-cycle summary are written to the Logbook
- Remove checkMkUrl from Device type, form, list view, and detail panel;
status badge and CheckMK panel only render when CheckMK is enabled
- Booking offline warning suppressed when CheckMK is disabled
- Topology status dot color driven purely by device.status
- Add SQLite settings table with getSetting/setSetting/getAllSettings helpers
- Implement Azure OAuth2 authorization code flow via @azure/msal-node
- Add public GET /api/auth/config endpoint for frontend activation check
- Add admin-only GET/PUT /api/settings API with masked secret fields
- CheckMK sync reads credentials from DB settings (env vars as fallback)
- New Settings.tsx: Entra ID and CheckMK configuration cards
- LoginPage: "Sign in with Microsoft" button, shown only when Azure is active
- App.tsx: OAuth callback handling (?token=/?auth_error=), Settings tab for admins
