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/services/notification_service.dart

@@ -248,7 +248,7 @@ class NotificationService {
       await _notifications.show(
         id: contactId != null
             ? 'advert:$contactId'.hashCode
-            : DateTime.now().millisecondsSinceEpoch,
+            : DateTime.now().millisecondsSinceEpoch & 0x7FFFFFFF,
         title: _l10n.notification_newTypeDiscovered(contactType),
         body: contactName,
         notificationDetails: notificationDetails,
@@ -304,7 +304,8 @@ class NotificationService {
 
     try {
       await _notifications.show(
-        id: channelIndex?.hashCode ?? DateTime.now().millisecondsSinceEpoch,
+        id: channelIndex?.hashCode ??
+            DateTime.now().millisecondsSinceEpoch & 0x7FFFFFFF,
         title: channelName,
         body: body,
         notificationDetails: notificationDetails,