v0.24.0 — Pre-testing observability: debug logging, diagnostic dump, startup self-test

- Add [DEBUG] logging across all modules (backup, storage, sync, selfupdate,
  monitor, notify, report, assets, setup) gated behind logging.level: "debug"
- Add /api/debug/dump endpoint returning full controller state JSON (debug only)
- Add startup self-test validating 9 subsystems (Docker, dirs, storage, hub,
  restic repos, metrics DB) with pass/warn/fail summary
- New packages: internal/selftest, internal/util
- Constructor/signature changes: debug bool params, logger params on
  RunHealthCheck and BuildReport, smart watchdog probe logging

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

controller/internal/web/storage_handlers.go

@@ -197,7 +197,7 @@ func (s *Server) storageAPIHandler(w http.ResponseWriter, r *http.Request) {
 
 // storageScanAPIHandler handles POST /api/storage/scan.
 func (s *Server) storageScanAPIHandler(w http.ResponseWriter, r *http.Request) {
-	result, err := storage.ScanDisks()
+	result, err := storage.ScanDisks(s.logger, s.cfg.Logging.Level == "debug")
 	if err != nil {
 		s.logger.Printf("[ERROR] storageScan: %v", err)
 		jsonError(w, "Meghajtók keresése sikertelen: "+err.Error(), http.StatusInternalServerError)
@@ -249,12 +249,14 @@ func (s *Server) storageInitAPIHandler(w http.ResponseWriter, r *http.Request) {
 		Label:           req.Label,
 		CreatePartition: req.CreatePartition,
 		SetDefault:      req.SetDefault,
+		Logger:          s.logger,
+		Debug:           s.cfg.Logging.Level == "debug",
 	}
 
 	// Smart partition: if disk has exactly 1 partition with no filesystem,
 	// skip destructive repartitioning and format the existing partition directly.
 	if fmtReq.CreatePartition {
-		if scanResult, scanErr := storage.ScanDisks(); scanErr == nil {
+		if scanResult, scanErr := storage.ScanDisks(s.logger, s.cfg.Logging.Level == "debug"); scanErr == nil {
 			for _, disk := range scanResult.AvailableDisks {
 				if disk.Path == req.DevicePath && len(disk.Partitions) == 1 && disk.Partitions[0].FSType == "" {
 					s.logger.Printf("[INFO] Disk %s has 1 empty partition (%s) — skipping repartition",
@@ -493,6 +495,8 @@ func (s *Server) storageMigrateAPIHandler(w http.ResponseWriter, r *http.Request
 		CurrentHDDPath: currentHDDPath,
 		TargetPath:     req.TargetPath,
 		HDDMounts:      mounts,
+		Logger:         s.logger,
+		Debug:          s.cfg.Logging.Level == "debug",
 	}
 
 	stopFn := func(name string) error {
@@ -1037,6 +1041,8 @@ func (s *Server) storageAttachAPIHandler(w http.ResponseWriter, r *http.Request)
 		SubPath:    req.SubPath,
 		Label:      req.Label,
 		SetDefault: req.SetDefault,
+		Logger:     s.logger,
+		Debug:      s.cfg.Logging.Level == "debug",
 	}
 
 	go func() {