debug(author): add detailed command logging to runCommandWithLogger

Enhanced runCommandWithLogger to log:
1. The exact command being executed (before execution)
2. Any errors when starting the command
3. Exit codes when commands fail

Before:
- No visibility into what command failed
- Silent failures during menu generation
- Log just showed "ERROR: FFmpeg failed during DVD encoding"

After:
- >> /usr/bin/ffmpeg [args...] (shows exact command)
- ERROR starting command: [error] (if command won't start)
- ERROR command failed: [error] (exit code: X) (if command fails)

This will help diagnose the menu generation failures by showing exactly
what FFmpeg command is failing and why.

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

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

author_module.go

@@ -3248,6 +3248,11 @@ Title: %s
 }
 
 func runCommandWithLogger(ctx context.Context, name string, args []string, logFn func(string)) error {
+	// Log the command being executed for debugging
+	if logFn != nil {
+		logFn(fmt.Sprintf(">> %s %s", name, strings.Join(args, " ")))
+	}
+
 	cmd := exec.CommandContext(ctx, name, args...)
 	utils.ApplyNoWindow(cmd)
 	stdout, err := cmd.StdoutPipe()
@@ -3260,6 +3265,9 @@ func runCommandWithLogger(ctx context.Context, name string, args []string, logFn
 	}
 
 	if err := cmd.Start(); err != nil {
+		if logFn != nil {
+			logFn(fmt.Sprintf("ERROR starting command: %v", err))
+		}
 		return fmt.Errorf("%s start: %w", name, err)
 	}
 
@@ -3281,6 +3289,9 @@ func runCommandWithLogger(ctx context.Context, name string, args []string, logFn
 	err = cmd.Wait()
 	wg.Wait()
 	if err != nil {
+		if logFn != nil {
+			logFn(fmt.Sprintf("ERROR command failed: %v (exit code: %v)", err, cmd.ProcessState.ExitCode()))
+		}
 		return fmt.Errorf("%s failed: %w", name, err)
 	}
 	return nil