The widget was failing to decode the cached timer data because WidgetTimer
struct didn't match the OngoingTimer JSON structure saved by the app.
Changes:
- Added missing fields (project, createdAt, updatedAt) to WidgetTimer
- Added WidgetProjectReference struct for nested project data
- Fixed project name to use project.name instead of projectId
- Added project color support
- Increased refresh interval from 15 min to 1 min for live updates
