v0.12.4 — 15 bug fixes (CRITICAL/HIGH/MEDIUM)

CRITICAL:
- C1: SetAppBackupBulk data loss + nil map panic (settings.go)
- C2: UpdateStackConfig nil Env map panic (deploy.go)
- C3: ValidateDump missing scanner.Err() check (dbdump.go)

HIGH:
- H1: nextDailyRun DST bug — use time.Date(day+1) not Add(24h)
- H2: Cache Europe/Budapest timezone with sync.Once in scheduler
- H3: settings.save() leaks .tmp file on WriteFile failure
- H4: SetNotificationPrefs nil pointer panic
- H5: appDirSize + getDirSizeBytes ignore Sscanf return value
- H6: getDirSizeBytes has no timeout — add 30s context
- H7: dbdump.go tmpFile not using defer Close
- H8: UpdateCrossDriveStatus misleading comment

MEDIUM:
- M1: Replace custom containsBytes with strings.Contains
- M2: scheduler.Every() validates interval > 0
- M3: executeJob panic recovery now sets LastRun
- M4: logPostStartStatus copies env slice before goroutine
- M5: Cache timezone in web package via getTimezone() sync.Once

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

controller/internal/backup/appdata.go

@@ -147,7 +147,9 @@ func appDirSize(path string) (int64, string) {
 		return 0, "?"
 	}
 	var size int64
-	fmt.Sscanf(fields[0], "%d", &size)
+	if n, _ := fmt.Sscanf(fields[0], "%d", &size); n != 1 {
+		return 0, "?"
+	}
 	return size, humanizeBytes(size)
 }
 

controller/internal/backup/dbdump.go

@@ -181,13 +181,13 @@ func DumpOne(ctx context.Context, db DiscoveredDB, dumpDir string, logger *log.L
 		result.Duration = time.Since(start)
 		return result
 	}
+	defer tmpFile.Close()
 
 	cmd.Stdout = tmpFile
 	var stderr strings.Builder
 	cmd.Stderr = &stderr
 
 	err = cmd.Run()
-	tmpFile.Close()
 
 	if err != nil {
 		os.Remove(tmpPath)
@@ -293,6 +293,13 @@ func ValidateDump(filePath string, dbType DBType) DumpValidation {
 			tableCount++
 		}
 	}
+
+	if err := scanner.Err(); err != nil {
+		v.Error = fmt.Sprintf("hiba az olvasás közben: %v", err)
+		log.Printf("[WARN] ValidateDump FAIL: %s — scanner error: %v", filePath, err)
+		return v
+	}
+
 	v.TableCount = tableCount
 
 	if !headerFound {