feat: add contact UI helpers and path editor for routing management

- Implemented contactTypeIcon and contactTypeColor functions for better UI representation of contact types.
- Created colorForName and firstCharacterOrEmoji functions to enhance contact display.
- Developed PathEditorSheet widget for managing contact paths with a user-friendly interface.
- Introduced RoutingSheet for managing contact routing modes and displaying path history.
- Added a script for generating proof of concept (PoC) payloads for clipboard contact import validation.

lib/widgets/snr_indicator.dart

@@ -166,7 +166,7 @@ class _SNRIndicatorState extends State<SNRIndicator> {
                   style: TextStyle(
                     fontSize: 12,
                     fontWeight: FontWeight.w500,
-                    color: Colors.grey,
+                    color: Theme.of(context).colorScheme.onSurfaceVariant,
                   ),
                   maxLines: 1,
                   overflow: TextOverflow.ellipsis,