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/selfupdate/updater.go

@@ -40,6 +40,7 @@ type Updater struct {
 	dataDir     string
 	composePath string // e.g., "/opt/docker/felhom-controller/docker-compose.yml"
 	logger      *log.Logger
+	debug       bool
 
 	mu            sync.Mutex
 	latestVersion string
@@ -49,7 +50,7 @@ type Updater struct {
 }
 
 // NewUpdater creates a new Updater instance.
-func NewUpdater(cfg *config.SelfUpdateConfig, gitCfg *config.GitConfig, currentVersion, dataDir, composePath string, logger *log.Logger) *Updater {
+func NewUpdater(cfg *config.SelfUpdateConfig, gitCfg *config.GitConfig, currentVersion, dataDir, composePath string, logger *log.Logger, debug bool) *Updater {
 	return &Updater{
 		cfg:         cfg,
 		gitCfg:      gitCfg,
@@ -57,6 +58,7 @@ func NewUpdater(cfg *config.SelfUpdateConfig, gitCfg *config.GitConfig, currentV
 		dataDir:     dataDir,
 		composePath: composePath,
 		logger:      logger,
+		debug:       debug,
 	}
 }
 
@@ -131,10 +133,16 @@ func (u *Updater) CheckForUpdate() CheckResult {
 		return result
 	}
 
-	if latestVer.Compare(currentVer) > 0 {
+	cmp := latestVer.Compare(currentVer)
+	if cmp > 0 {
 		result.UpdateAvailable = true
 	}
 
+	if u.debug {
+		u.logger.Printf("[DEBUG] [SELFUPDATE] Version comparison: current=%s, latest=%s, cmp=%d, updateAvailable=%v",
+			u.currentVer, latestStr, cmp, result.UpdateAvailable)
+	}
+
 	u.mu.Lock()
 	u.latestVersion = latestStr
 	u.lastCheck = &result
@@ -153,6 +161,10 @@ func (u *Updater) queryRegistry() (string, error) {
 	// Gitea registry V2: GET /v2/<owner>/<repo>/tags/list
 	url := fmt.Sprintf("https://gitea.dooplex.hu/v2/%s/tags/list", registryImagePath(u.cfg.Image))
 
+	if u.debug {
+		u.logger.Printf("[DEBUG] [SELFUPDATE] Registry API URL: %s (user: %s)", url, u.gitCfg.Username)
+	}
+
 	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {
 		return "", fmt.Errorf("creating request: %w", err)
@@ -181,6 +193,10 @@ func (u *Updater) queryRegistry() (string, error) {
 		return "", fmt.Errorf("decoding response: %w", err)
 	}
 
+	if u.debug {
+		u.logger.Printf("[DEBUG] [SELFUPDATE] Registry returned %d tags: %v", len(tagsResp.Tags), tagsResp.Tags)
+	}
+
 	// Find highest semver tag
 	var highest *Version
 	for _, tag := range tagsResp.Tags {
@@ -342,6 +358,15 @@ func (u *Updater) updateComposeFile(newImage string) error {
 
 	// Replace image line: "image: gitea.dooplex.hu/admin/felhom-controller:..." → new image
 	re := regexp.MustCompile(`(image:\s*)gitea\.dooplex\.hu/admin/felhom-controller:\S+`)
+
+	if u.debug {
+		// Log old image line for debugging
+		oldMatch := re.Find(data)
+		if oldMatch != nil {
+			u.logger.Printf("[DEBUG] [SELFUPDATE] Compose file edit: %q → %q", string(oldMatch), "image: "+newImage)
+		}
+	}
+
 	newData := re.ReplaceAll(data, []byte("${1}"+newImage))
 
 	if bytes.Equal(data, newData) {