feat(author): add timestamp prefix to log filenames for chronological sorting

Changed log filename format from:
  ifuckedmybestfriendsgirlfriend-author.videotools.log

To:
  20260109_220355-ifuckedmybestfriendsgirlfriend-author.videotools.log

Benefits:
- Chronological sorting: Files sort by creation time in file browsers
- No overwrites: Each authoring job creates a unique log file
- Easy tracking: Timestamp shows exactly when the job was started
- Clean history: Can review logs from multiple runs of the same job

Timestamp format: YYYYMMDD_HHMMSS (e.g., 20260109_220355)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

author_module.go

@@ -3215,7 +3215,10 @@ func createAuthorLog(inputs []string, outputPath string, makeISO bool, region, a
 	if base == "" {
 		base = "author"
 	}
-	logPath := filepath.Join(getLogsDir(), base+"-author"+conversionLogSuffix)
+	// Add timestamp prefix for chronological sorting and uniqueness
+	timestamp := time.Now().Format("20060102_150405")
+	logFilename := fmt.Sprintf("%s-%s-author%s", timestamp, base, conversionLogSuffix)
+	logPath := filepath.Join(getLogsDir(), logFilename)
 	if err := os.MkdirAll(filepath.Dir(logPath), 0o755); err != nil {
 		return nil, logPath, fmt.Errorf("create log dir: %w", err)
 	}