feat: add aliases and deacon status line display

- Add 'bd' alias for 'gt bead' command
- Add 'work' alias for 'gt hook' command
- Show deacon icon in mayor status line when running

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

internal/cmd/bead.go

@@ -13,6 +13,7 @@ import (
 
 var beadCmd = &cobra.Command{
 	Use:     "bead",
+	Aliases: []string{"bd"},
 	GroupID: GroupWork,
 	Short:   "Bead management utilities",
 	Long:    `Utilities for managing beads across repositories.`,