auto-claude: subtask-1-2 - Add onboardingCompleted to DEFAULT_APP_SETTINGS

- Added onboardingCompleted: false to DEFAULT_APP_SETTINGS constant
- This provides the default value for the new onboarding tracking field

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

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

auto-claude-ui/src/shared/constants.ts

@@ -90,6 +90,7 @@ export const DEFAULT_APP_SETTINGS = {
   autoBuildPath: undefined as string | undefined,
   autoUpdateAutoBuild: true,
   autoNameTerminals: true,
+  onboardingCompleted: false,
   notifications: {
     onTaskComplete: true,
     onTaskFailed: true,