feat(types): add rig identity bead type (gt-zmznh)

- Add TypeRig constant to IssueType enum
- Update IsValid() method to include TypeRig
- Add UI color (orange) and style for rig type
- Update CLI flag descriptions in create and update commands
- Add Obsidian export tag for rig type
- Add comprehensive test cases for rig and other newer types

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

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

internal/ui/styles_test.go

@@ -94,6 +94,7 @@ func TestRenderTypeVariants(t *testing.T) {
 		{"chore", TypeChoreStyle.Render("chore")},
 		{"agent", TypeAgentStyle.Render("agent")},
 		{"role", TypeRoleStyle.Render("role")},
+		{"rig", TypeRigStyle.Render("rig")},
 		{"custom", "custom"},
 	}
 	for _, tc := range cases {