- Add content_hash and updated_at fields to 4 InstalledSkill literals in skill_sync.rs
- Add useCheckSkillUpdates and useUpdateSkill to UnifiedSkillsPanel test mock
- Suppress unused import warning in auto_launch.rs test module
Create a local backup under ~/.cc-switch/skill-backups/ before removing
skill directories. The backup includes all skill files and a meta.json
with original skill metadata. Old backups are pruned to keep at most 20.
The backup path is returned to the frontend and shown in the success
toast. Bump version to 3.12.3.