feat: Add --body flag as alias for --description

Adds --body as a hidden alias for --description in create/update commands,
following GitHub CLI convention for better agent ergonomics.

The --body flag:
- Works alongside existing --description and -d flags
- Hidden from help output to avoid clutter
- Validates conflicts when both flags used with different values
- Available in both 'bd create' and 'bd update' commands

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

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

cmd/bd/create.go

@@ -77,7 +77,7 @@ var createCmd = &cobra.Command{
 		}
 
 		// Get field values, preferring explicit flags over template defaults
-		description, _ := cmd.Flags().GetString("description")
+		description, _ := getDescriptionFlag(cmd)
 		if description == "" && tmpl != nil {
 			description = tmpl.Description
 		}

cmd/bd/flags.go

@@ -1,16 +1,51 @@
 package main
 
-import "github.com/spf13/cobra"
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
 
 // registerCommonIssueFlags registers flags common to create and update commands.
 func registerCommonIssueFlags(cmd *cobra.Command) {
 	cmd.Flags().StringP("assignee", "a", "", "Assignee")
 	cmd.Flags().StringP("description", "d", "", "Issue description")
+	cmd.Flags().String("body", "", "Alias for --description (GitHub CLI convention)")
+	_ = cmd.Flags().MarkHidden("body") // Hidden alias for agent/CLI ergonomics
 	cmd.Flags().String("design", "", "Design notes")
 	cmd.Flags().String("acceptance", "", "Acceptance criteria")
 	cmd.Flags().String("external-ref", "", "External reference (e.g., 'gh-9', 'jira-ABC')")
 }
 
+// getDescriptionFlag retrieves the description value, checking both --description and --body.
+// Returns the value and whether either flag was explicitly changed.
+func getDescriptionFlag(cmd *cobra.Command) (string, bool) {
+	descChanged := cmd.Flags().Changed("description")
+	bodyChanged := cmd.Flags().Changed("body")
+
+	// Error if both are specified with different values
+	if descChanged && bodyChanged {
+		desc, _ := cmd.Flags().GetString("description")
+		body, _ := cmd.Flags().GetString("body")
+		if desc != body {
+			fmt.Fprintf(os.Stderr, "Error: cannot specify both --description and --body with different values\n")
+			fmt.Fprintf(os.Stderr, "  --description: %q\n", desc)
+			fmt.Fprintf(os.Stderr, "  --body:        %q\n", body)
+			os.Exit(1)
+		}
+	}
+
+	// Return whichever was set (or description's value if neither)
+	if bodyChanged {
+		body, _ := cmd.Flags().GetString("body")
+		return body, true
+	}
+
+	desc, _ := cmd.Flags().GetString("description")
+	return desc, descChanged
+}
+
 // registerPriorityFlag registers the priority flag with a specific default value.
 func registerPriorityFlag(cmd *cobra.Command, defaultVal string) {
 	cmd.Flags().StringP("priority", "p", defaultVal, "Priority (0-4 or P0-P4, 0=highest)")

cmd/bd/show.go

@@ -368,8 +368,8 @@ var updateCmd = &cobra.Command{
 			assignee, _ := cmd.Flags().GetString("assignee")
 			updates["assignee"] = assignee
 		}
-		if cmd.Flags().Changed("description") {
-			description, _ := cmd.Flags().GetString("description")
+		description, descChanged := getDescriptionFlag(cmd)
+		if descChanged {
 			updates["description"] = description
 		}
 		if cmd.Flags().Changed("design") {