Add comprehensive tests for DrawingMessageParser and SarMessageParser

- Implement critical string formatting tests for DrawingMessageParser, ensuring correct message creation, parsing, and validation.
- Validate JSON structure, coordinate formatting, and color index preservation in drawing messages.
- Introduce tests for various drawing types, including LineDrawing and RectangleDrawing, with emphasis on output consistency and error handling.
- Add tests for SarMessageParser, covering message creation, parsing, and format validation, including backward compatibility with old formats.
- Ensure proper handling of special characters, empty notes, and extreme coordinate values in SAR messages.
- Validate that messages conform to the CLAUDE.md specification and maintain compactness and efficiency.

lib/widgets/contacts/contact_tile.dart

@@ -182,7 +182,25 @@ class ContactTile extends StatelessWidget {
                 crossAxisAlignment: CrossAxisAlignment.start,
                 children: [
                   const SizedBox(height: 4),
-                  // Simple mode: Only show location and distance
+                  // Simple mode: Show last update time
+                  Row(
+                    children: [
+                      Icon(
+                        Icons.access_time,
+                        size: 12,
+                        color: contact.isRecentlySeen
+                            ? Colors.green
+                            : Colors.grey,
+                      ),
+                      const SizedBox(width: 4),
+                      Text(
+                        '${AppLocalizations.of(context)!.lastSeen}: ${contact.timeSinceLastSeen}',
+                        style: Theme.of(context).textTheme.labelSmall,
+                      ),
+                    ],
+                  ),
+                  const SizedBox(height: 4),
+                  // Simple mode: Show location and distance
                   if (location != null) ...[
                     Row(
                       children: [