Fix iOS timer widget not displaying active timers

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

ios/TimeTracker/TimeTrackerWidget/TimeTrackerWidget.entitlements

@@ -3,6 +3,8 @@
 <plist version="1.0">
 <dict>
 	<key>com.apple.security.application-groups</key>
-	<array/>
+	<array>
+		<string>group.com.timetracker.app</string>
+	</array>
 </dict>
 </plist>