fix: update tests for InstalledSkill new fields and missing hook mocks

- 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

src-tauri/src/auto_launch.rs

@@ -70,6 +70,7 @@ pub fn is_auto_launch_enabled() -> Result<bool, AppError> {
 
 #[cfg(test)]
 mod tests {
+    #[allow(unused_imports)]
     use super::*;
 
     #[cfg(target_os = "macos")]