Migrate iOS app to system colors and improve UI/UX

- Remove AppColors struct, migrate to iOS system colors throughout
- Redesign ContractorFormSheet to use native SwiftUI Form components
- Add color-coded icons to contractor form sections
- Improve dark mode contrast for task cards
- Add background colors to document detail fields
- Fix text alignment issues in ContractorDetailView
- Make task completion lists expandable/collapsible by default
- Clear app badge on launch and when app becomes active
- Update button styling with proper gradients and shadows
- Improve form field focus states and accessibility

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

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

iosApp/iosApp/PushNotifications/AppDelegate.swift

@@ -16,9 +16,23 @@ class AppDelegate: NSObject, UIApplicationDelegate, UNUserNotificationCenterDele
             await PushNotificationManager.shared.requestNotificationPermission()
         }
 
+        // Clear badge when app launches
+        Task { @MainActor in
+            PushNotificationManager.shared.clearBadge()
+        }
+
         return true
     }
 
+    // MARK: - App Lifecycle
+
+    func applicationDidBecomeActive(_ application: UIApplication) {
+        // Clear badge when app becomes active
+        Task { @MainActor in
+            PushNotificationManager.shared.clearBadge()
+        }
+    }
+
     // MARK: - Remote Notifications
 
     func application(