feat: Enhance messaging and SAR marker functionalities

- Integrated SAR marker sending feature in MessagesTab with a dedicated dialog for user input.
- Updated message sending logic to default to the first available room if no contact is selected.
- Improved user feedback with SnackBars for connection issues and successful marker sends.
- Refactored contact selection to remove unused code and streamline the process.
- Added location fetching capabilities using Geolocator for SAR markers.
- Updated sample data with more relevant team names using emojis.
- Enhanced map markers to include rotation handling and improved display of contact information.
- Introduced color coding for location update age in map markers for better visibility.

.claude/settings.local.json

@@ -0,0 +1,9 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(flutter analyze:*)"
+    ],
+    "deny": [],
+    "ask": []
+  }
+}