fix: standardize log prefixes, remove duplicates, add missing module tags

Second-pass logging cleanup: consistent [LEVEL] [module] format across
all 41 files. Remove stale prefixes ([CF], [SYNC], [SCHED], [API],
[STORAGE], [HEALTH], [ROLLBACK]). Remove 5 duplicate log lines. Gate
ungated DEBUG lines. Fix wrong log levels (restore start WARN→INFO).

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

controller/internal/backup/restic.go

@@ -88,7 +88,7 @@ func (r *ResticManager) EnsureInitialized(repoPath string) error {
 	// Check if repo is already initialized
 	configPath := filepath.Join(repoPath, "config")
 	if _, err := os.Stat(configPath); err == nil {
-		r.logger.Printf("[INFO] Restic repo already initialized at %s", repoPath)
+		r.logger.Printf("[INFO] [backup] Restic repo already initialized at %s", repoPath)
 		return nil
 	}
 
@@ -98,7 +98,7 @@ func (r *ResticManager) EnsureInitialized(repoPath string) error {
 	}
 
 	// Initialize repo
-	r.logger.Printf("[INFO] Initializing restic repository at %s", repoPath)
+	r.logger.Printf("[INFO] [backup] Initializing restic repository at %s", repoPath)
 	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
 	defer cancel()
 
@@ -108,7 +108,7 @@ func (r *ResticManager) EnsureInitialized(repoPath string) error {
 		return fmt.Errorf("restic init failed: %v — %s", err, truncate(string(out), 200))
 	}
 
-	r.logger.Printf("[INFO] Restic repository initialized successfully")
+	r.logger.Printf("[INFO] [backup] Restic repository initialized successfully")
 	return nil
 }
 
@@ -134,7 +134,7 @@ func (r *ResticManager) Snapshot(repoPath string, paths []string, tags []string)
 		if _, err := os.Stat(p); err == nil {
 			existingPaths = append(existingPaths, p)
 		} else {
-			r.logger.Printf("[WARN] Backup path does not exist, skipping: %s", p)
+			r.logger.Printf("[WARN] [backup] Backup path does not exist, skipping: %s", p)
 		}
 	}
 
@@ -155,10 +155,10 @@ func (r *ResticManager) Snapshot(repoPath string, paths []string, tags []string)
 			errStr += string(exitErr.Stderr)
 		}
 		if strings.Contains(errStr, "lock") || strings.Contains(errStr, "locked") {
-			r.logger.Printf("[WARN] Restic repo locked — attempting unlock")
+			r.logger.Printf("[WARN] [backup] Restic repo locked — attempting unlock")
 			unlockCmd := r.command(ctx, repoPath, "unlock")
 			if unlockErr := unlockCmd.Run(); unlockErr != nil {
-				r.logger.Printf("[WARN] Restic unlock failed: %v", unlockErr)
+				r.logger.Printf("[WARN] [backup] Restic unlock failed: %v", unlockErr)
 			}
 			// Retry once with a fresh context (H9 fix — original may be nearly expired).
 			retryCtx, retryCancel := context.WithTimeout(context.Background(), 30*time.Minute)
@@ -239,7 +239,7 @@ func (r *ResticManager) Prune(repoPath string, retention config.RetentionConfig)
 	if r.debug {
 		r.logger.Printf("[DEBUG] [restic] Prune: completed in %s, output=%d bytes", time.Since(start), len(out))
 	}
-	r.logger.Printf("[INFO] Restic prune completed for %s", repoPath)
+	r.logger.Printf("[INFO] [backup] Restic prune completed for %s", repoPath)
 	return nil
 }
 
@@ -420,19 +420,19 @@ func (r *ResticManager) RestoreAppData(repoPath string, snapshotID string, paths
 	}
 	start := time.Now()
 
-	r.logger.Printf("[WARN] RESTORE started: repo=%s, snapshot=%s, paths=%v", repoPath, snapshotID, paths)
+	r.logger.Printf("[INFO] [backup] Restore started: repo=%s, snapshot=%s, paths=%v", repoPath, snapshotID, paths)
 
 	cmd := r.command(ctx, repoPath, args...)
 	output, err := cmd.CombinedOutput()
 	if err != nil {
-		r.logger.Printf("[ERROR] Restore failed: %v, output: %s", err, truncate(string(output), 500))
+		r.logger.Printf("[ERROR] [backup] Restore failed: %v, output: %s", err, truncate(string(output), 500))
 		return fmt.Errorf("restic restore failed: %w", err)
 	}
 
 	if r.debug {
 		r.logger.Printf("[DEBUG] [restic] RestoreAppData: completed in %s, output=%d bytes", time.Since(start), len(output))
 	}
-	r.logger.Printf("[INFO] RESTORE completed: snapshot=%s, paths=%v", snapshotID, paths)
+	r.logger.Printf("[INFO] [backup] Restore completed: snapshot=%s, paths=%v", snapshotID, paths)
 	return nil
 }
 
@@ -483,8 +483,8 @@ func (r *ResticManager) generatePassword() error {
 		return fmt.Errorf("writing password file: %w", err)
 	}
 
-	r.logger.Printf("[INFO] Generated new restic repository password at %s", r.passwordFile)
-	r.logger.Printf("[WARN] Save this password externally — losing it means losing access to ALL backups")
+	r.logger.Printf("[INFO] [backup] Generated new restic repository password at %s", r.passwordFile)
+	r.logger.Printf("[WARN] [backup] Save this password externally — losing it means losing access to ALL backups")
 	return nil
 }