feat: drive migration & Tier 2 restic deprecation (v0.18.0)

Phase 1: Deprecate restic as Tier 2 method (rsync only), auto-migrate on startup
Phase 2: Enhanced per-app migration with backup awareness, DB dump copy, auto-cleanup
Phase 3: Full drive migration with decommissioned state, rollback support, wizard UI
Phase 4: Hub report includes decommissioned drive state

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

controller/internal/web/server.go

@@ -18,6 +18,7 @@ import (
 	"gitea.dooplex.hu/admin/felhom-controller/internal/selfupdate"
 	"gitea.dooplex.hu/admin/felhom-controller/internal/settings"
 	"gitea.dooplex.hu/admin/felhom-controller/internal/stacks"
+	"gitea.dooplex.hu/admin/felhom-controller/internal/storage"
 	"gitea.dooplex.hu/admin/felhom-controller/internal/system"
 )
 
@@ -47,6 +48,9 @@ type Server struct {
 	// Active raw mount for the attach wizard (empty when not in use)
 	activeRawMount string
 
+	// Drive migration
+	driveMigrator *storage.DriveMigrator
+
 	// DR restore mode state
 	restoreMu   sync.RWMutex
 	restorePlan *backup.RestorePlan
@@ -85,7 +89,7 @@ func NewServer(cfg *config.Config, stackMgr *stacks.Manager, cpuCollector *syste
 	}
 
 	// Sync FileBrowser config on startup to ensure mounts and sources are current
-	go s.syncFileBrowserMounts()
+	go s.SyncFileBrowserMounts()
 
 	return s
 }
@@ -108,6 +112,11 @@ func (s *Server) SetStorageWatchdog(w *monitor.StorageWatchdog) {
 	s.storageWatchdog = w
 }
 
+// SetDriveMigrator sets the drive migration engine for full drive migration.
+func (s *Server) SetDriveMigrator(dm *storage.DriveMigrator) {
+	s.driveMigrator = dm
+}
+
 // InRestoreMode returns true if the server is in DR restore mode.
 func (s *Server) InRestoreMode() bool {
 	s.restoreMu.RLock()
@@ -179,6 +188,8 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		s.storageInitHandler(w, r)
 	case path == "/settings/storage/attach":
 		s.storageAttachHandler(w, r)
+	case path == "/settings/storage/migrate-drive":
+		s.migrateDrivePageHandler(w, r)
 	case strings.HasPrefix(path, "/stacks/") && strings.HasSuffix(path, "/migrate"):
 		name := strings.TrimPrefix(path, "/stacks/")
 		name = strings.TrimSuffix(name, "/migrate")