Dev discovery (#291)

* Refactor contact handling: replace DiscoveryContact with Contact, update related methods and settings

* Enhance contact handling: include latitude, longitude, and last modified timestamp in contact updates; refactor path handling to accommodate discovered contacts across multiple screens

* Enhance SNRIndicator: include discovered contacts in name resolution for repeaters

* Refactor path handling: replace addReturnPath with buildPath to improve path construction logic and handle target contact types

* Update lib/screens/map_screen.dart

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Add localization for "Show Discovery Contacts" in multiple languages and refactor location plausibility check in map screen

* Enhance contact management: update discovered contacts' active status and improve contact handling with flags and raw packet data

* Refactor ChannelsScreen: pass ChannelMessageStore to buildExpandedContent and ensure messages are cleared after channel creation

* Update MapScreen: adjust label zoom threshold and refactor guessed marker building to include labels

* Refactor ChannelsScreen: change channelMessageStore to a private getter and update its usage in buildExpandedContent calls

* Enhance location plausibility check: add latitude and longitude bounds to ensure valid coordinates

* Update lib/connector/meshcore_connector.dart

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Refactor MeshCoreConnector and related stores: update discovered contacts handling, migrate legacy keys, and set public key in community store

* Refactor MeshCoreConnector and ChannelsScreen: update discovered contacts handling and set public key in community store; enhance location plausibility check in MapScreen

* Update CMD_ADD_UPDATE_CONTACT frame format to include optional latitude and longitude fields

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

lib/models/contact.dart

@@ -17,6 +17,8 @@ class Contact {
   final double? longitude;
   final DateTime lastSeen;
   final DateTime lastMessageAt;
+  final bool isActive;
+  final Uint8List? rawPacket;
 
   Contact({
     required this.publicKey,
@@ -31,6 +33,8 @@ class Contact {
     this.longitude,
     required this.lastSeen,
     DateTime? lastMessageAt,
+    this.isActive = true,
+    this.rawPacket,
   }) : lastMessageAt = lastMessageAt ?? lastSeen;
 
   String get publicKeyHex => pubKeyToHex(publicKey);
@@ -78,6 +82,8 @@ class Contact {
     double? longitude,
     DateTime? lastSeen,
     DateTime? lastMessageAt,
+    bool? isActive,
+    Uint8List? rawPacket,
   }) {
     return Contact(
       publicKey: publicKey ?? this.publicKey,
@@ -96,6 +102,8 @@ class Contact {
       longitude: longitude ?? this.longitude,
       lastSeen: lastSeen ?? this.lastSeen,
       lastMessageAt: lastMessageAt ?? this.lastMessageAt,
+      isActive: isActive ?? this.isActive,
+      rawPacket: rawPacket ?? this.rawPacket,
     );
   }
 
@@ -204,6 +212,8 @@ class Contact {
         latitude: lat,
         longitude: lon,
         lastSeen: DateTime.fromMillisecondsSinceEpoch(lastMod * 1000),
+        isActive: true,
+        rawPacket: null,
       );
     } catch (e) {
       appLogger.error('Failed to parse contact frame: $e');