M5: notifications, setup check, audit log and password confirmation

- notifications to administrators for failed backup/restore runs and
  locations without a successful backup for two days (once a day)
- setup check in the admin overview: error when the key/kit is not set
  up, warning for missing, old or failed backups
- security events (recovery kit downloaded, location removed,
  append-only turned off, retention changed, snapshots forgotten) go to
  the audit log and are announced to all administrators, from the web
  and from occ; the scheduled weekly cleanup is logged only
- fix: the recovery-kit download link failed the CSRF check (412); it
  now requires a recent password confirmation instead, like creating the
  key, removing a location and restoring

package-lock.json

@@ -12,6 +12,7 @@
 				"@nextcloud/axios": "^2.5.1",
 				"@nextcloud/dialogs": "^7.4.0",
 				"@nextcloud/l10n": "^3.4.0",
+				"@nextcloud/password-confirmation": "^6.1.0",
 				"@nextcloud/router": "^3.0.1",
 				"@nextcloud/vue": "^9.0.0",
 				"vue": "^3.5.0"
@@ -885,6 +886,24 @@
 				"node": "^20.0.0 || ^22.0.0 || ^24.0.0"
 			}
 		},
+		"node_modules/@nextcloud/password-confirmation": {
+			"version": "6.1.0",
+			"resolved": "https://registry.npmjs.org/@nextcloud/password-confirmation/-/password-confirmation-6.1.0.tgz",
+			"integrity": "sha512-N2ChXDbPcUcQCoAjj1yc65zfc61yiKpdM3qm/y3Y/y//NG7XWNNINwBg85lqJ2SISgmVStpsQ1d0blpFCoQXkQ==",
+			"license": "MIT",
+			"dependencies": {
+				"@nextcloud/auth": "^2.5.3",
+				"@nextcloud/axios": "^2.5.2",
+				"@nextcloud/l10n": "^3.4.1",
+				"@nextcloud/logger": "^3.0.3",
+				"@nextcloud/router": "^3.1.0",
+				"@nextcloud/vue": "^9.6.0",
+				"vue": "^3.5.30"
+			},
+			"engines": {
+				"node": "^20.0.0 || ^22.0.0 || ^24.0.0"
+			}
+		},
 		"node_modules/@nextcloud/paths": {
 			"version": "3.1.0",
 			"resolved": "https://registry.npmjs.org/@nextcloud/paths/-/paths-3.1.0.tgz",