feat(cmd): add --comment as alias for --reason in gt close

Add support for --comment flag as an alias for --reason in the
gt close command. This provides a more intuitive option name for
users who think of close messages as comments rather than reasons.

Handles both --comment value and --comment=value forms.

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

internal/cmd/close.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"os"
 	"os/exec"
+	"strings"
 
 	"github.com/spf13/cobra"
 )
@@ -20,6 +21,7 @@ Examples:
   gt close gt-abc              # Close bead gt-abc
   gt close gt-abc gt-def       # Close multiple beads
   gt close --reason "Done"     # Close with reason
+  gt close --comment "Done"    # Same as --reason (alias)
   gt close --force             # Force close pinned beads`,
 	DisableFlagParsing: true, // Pass all flags through to bd close
 	RunE:               runClose,
@@ -30,8 +32,20 @@ func init() {
 }
 
 func runClose(cmd *cobra.Command, args []string) error {
+	// Convert --comment to --reason (alias support)
+	convertedArgs := make([]string, len(args))
+	for i, arg := range args {
+		if arg == "--comment" {
+			convertedArgs[i] = "--reason"
+		} else if strings.HasPrefix(arg, "--comment=") {
+			convertedArgs[i] = "--reason=" + strings.TrimPrefix(arg, "--comment=")
+		} else {
+			convertedArgs[i] = arg
+		}
+	}
+
 	// Build bd close command with all args passed through
-	bdArgs := append([]string{"close"}, args...)
+	bdArgs := append([]string{"close"}, convertedArgs...)
 	bdCmd := exec.Command("bd", bdArgs...)
 	bdCmd.Stdin = os.Stdin
 	bdCmd.Stdout = os.Stdout