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/helpers/contact_ui.dart

@@ -0,0 +1,59 @@
+import 'package:flutter/material.dart';
+
+import '../connector/meshcore_protocol.dart';
+import '../utils/emoji_utils.dart';
+
+IconData contactTypeIcon(int type) {
+  switch (type) {
+    case advTypeChat:
+      return Icons.chat;
+    case advTypeRepeater:
+      return Icons.cell_tower;
+    case advTypeRoom:
+      return Icons.group;
+    case advTypeSensor:
+      return Icons.sensors;
+    default:
+      return Icons.device_unknown;
+  }
+}
+
+Color contactTypeColor(int type) {
+  switch (type) {
+    case advTypeChat:
+      return Colors.blue;
+    case advTypeRepeater:
+      return Colors.orange;
+    case advTypeRoom:
+      return Colors.purple;
+    case advTypeSensor:
+      return Colors.green;
+    default:
+      return Colors.grey;
+  }
+}
+
+Color colorForName(String name) {
+  const colors = [
+    Colors.blue,
+    Colors.green,
+    Colors.orange,
+    Colors.purple,
+    Colors.pink,
+    Colors.teal,
+    Colors.indigo,
+    Colors.cyan,
+    Colors.amber,
+    Colors.deepOrange,
+  ];
+  return colors[name.hashCode.abs() % colors.length];
+}
+
+String firstCharacterOrEmoji(String name) {
+  if (name.isEmpty) return '?';
+  final emoji = firstEmoji(name);
+  if (emoji != null) return emoji;
+  final runes = name.runes.toList();
+  if (runes.isEmpty) return '?';
+  return String.fromCharCode(runes[0]).toUpperCase();
+}