v0.11.8 — Per-App Cross-Drive Backup (3-2-1 rule)

New feature: backup app data to a secondary storage drive to satisfy
the "different media" requirement of the 3-2-1 backup rule.

- settings.go: CrossDriveBackup struct, AppBackupPrefs.CrossDrive field,
  getter/setter methods, GetOrCreateCrossDrivePassword, preserves
  cross-drive config when toggling nightly backup

- crossdrive.go (new): CrossDriveRunner with rsync and restic backends.
  Validates destination (mount point, writable), prevents source/dest
  overlap, per-app concurrency lock, persists last_run/status/size.

- main.go: wire CrossDriveRunner, register cross-drive-daily (03:30)
  and cross-drive-weekly (04:30 Sundays) scheduler jobs

- router.go: 4 new API endpoints — save config, trigger run, get status,
  run-all. Router now accepts Settings and CrossDriveRunner.

- server.go: Server struct accepts CrossDriveRunner, new web route
  POST /settings/cross-backup/{name}

- handlers.go: deployHandler populates CrossDriveConfig, BackupDestPaths,
  BackupDestWarning, AppBackupEnabled. settingsCrossBackupHandler saves
  config. backupsHandler builds CrossDriveSummary, UnconfiguredApps,
  CrossDriveWarnings for backup page.

- deploy.html: "Biztonsági mentés" card with destination/method/schedule
  dropdowns, last-run status, manual trigger button, flash messages.

- backups.html: "Másolatok másik meghajtóra" section with per-app
  status rows, unconfigured app warnings, "Összes futtatása most" button.

- style.css: margin-bottom fix for .deploy-stale-data, new cross-drive
  card and list styles.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

controller/internal/web/server.go

@@ -20,17 +20,18 @@ import (
 )
 
 type Server struct {
-	cfg          *config.Config
-	stackMgr     *stacks.Manager
-	cpuCollector *system.CPUCollector
-	backupMgr    *backup.Manager
-	scheduler    *scheduler.Scheduler
-	settings     *settings.Settings
-	alertManager *AlertManager
-	notifier     *notify.Notifier
-	logger       *log.Logger
-	version      string
-	tmpl         *template.Template
+	cfg              *config.Config
+	stackMgr         *stacks.Manager
+	cpuCollector     *system.CPUCollector
+	backupMgr        *backup.Manager
+	crossDriveRunner *backup.CrossDriveRunner
+	scheduler        *scheduler.Scheduler
+	settings         *settings.Settings
+	alertManager     *AlertManager
+	notifier         *notify.Notifier
+	logger           *log.Logger
+	version          string
+	tmpl             *template.Template
 
 	sessions   map[string]*session
 	sessionsMu sync.RWMutex
@@ -41,20 +42,21 @@ type Server struct {
 	diskJob   *activeDiskJob
 }
 
-func NewServer(cfg *config.Config, stackMgr *stacks.Manager, cpuCollector *system.CPUCollector, backupMgr *backup.Manager, sched *scheduler.Scheduler, sett *settings.Settings, alertMgr *AlertManager, notif *notify.Notifier, logger *log.Logger, version string) *Server {
+func NewServer(cfg *config.Config, stackMgr *stacks.Manager, cpuCollector *system.CPUCollector, backupMgr *backup.Manager, crossDrive *backup.CrossDriveRunner, sched *scheduler.Scheduler, sett *settings.Settings, alertMgr *AlertManager, notif *notify.Notifier, logger *log.Logger, version string) *Server {
 	s := &Server{
-		cfg:          cfg,
-		stackMgr:     stackMgr,
-		cpuCollector: cpuCollector,
-		backupMgr:    backupMgr,
-		scheduler:    sched,
-		settings:     sett,
-		alertManager: alertMgr,
-		notifier:     notif,
-		logger:       logger,
-		version:      version,
-		sessions:     make(map[string]*session),
-		done:         make(chan struct{}),
+		cfg:              cfg,
+		stackMgr:         stackMgr,
+		cpuCollector:     cpuCollector,
+		backupMgr:        backupMgr,
+		crossDriveRunner: crossDrive,
+		scheduler:        sched,
+		settings:         sett,
+		alertManager:     alertMgr,
+		notifier:         notif,
+		logger:           logger,
+		version:          version,
+		sessions:         make(map[string]*session),
+		done:             make(chan struct{}),
 	}
 	s.loadTemplates()
 	go s.cleanupSessions()
@@ -110,6 +112,9 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		s.settingsStorageLabelHandler(w, r)
 	case path == "/settings/app-backup" && r.Method == http.MethodPost:
 		s.settingsAppBackupHandler(w, r)
+	case strings.HasPrefix(path, "/settings/cross-backup/") && r.Method == http.MethodPost:
+		name := strings.TrimPrefix(path, "/settings/cross-backup/")
+		s.settingsCrossBackupHandler(w, r, name)
 	case path == "/backup/restore" && r.Method == http.MethodPost:
 		s.backupRestoreHandler(w, r)
 	case path == "/settings/storage/init":