fix(#151): widen DirectRepeater to configured path-hash width (Nearby Repeaters)

DirectRepeater stored only pubkeyFirstByte (1 byte of the last hop), so the SNR
indicator + Nearby Repeaters dialog showed a 1-byte prefix and matched the wrong
repeater on 2-/3-byte path-hash meshes. Capture the last hop's full configured-
width prefix and use it for display, contact-match, and dedup.

- DirectRepeater.pubkeyPrefix (Uint8List) + prefixHex getter; pubkeyFirstByte
  retained for the path-management / chat matching sites (those are #156).
- _updateDirectRepeater captures path[len-width..] (or the pubkey prefix when no
  path); dedup by listEquals(pubkeyPrefix).
- snr_indicator: status-bar + dialog render prefixHex; matcher keys on the full
  width prefix so the correct repeater name resolves.

Bumps build to +45. analyze clean; 6 DirectRepeater tests (2 new); Gemini: ship.

Closes #151

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/connector/meshcore_connector.dart

@@ -51,15 +51,23 @@ import 'meshcore_protocol.dart';
 class DirectRepeater {
   static const int maxAgeMinutes = 30; // Max age for direct repeater info
   final int pubkeyFirstByte;
+  // Last-hop prefix at the device's configured path-hash width (1/2/3 bytes), so
+  // 2-/3-byte meshes display + match the full repeater prefix, not just 1 byte. (#151)
+  final Uint8List pubkeyPrefix;
   double snr;
   DateTime lastUpdated;
 
   DirectRepeater({
     required this.pubkeyFirstByte,
+    required this.pubkeyPrefix,
     required this.snr,
     DateTime? lastUpdated,
   }) : lastUpdated = lastUpdated ?? DateTime.now();
 
+  /// Last-hop prefix as lowercase hex (2 chars per byte). (#151)
+  String get prefixHex =>
+      pubkeyPrefix.map((b) => b.toRadixString(16).padLeft(2, '0')).join();
+
   void update(double newSNR) {
     snr = newSNR;
     lastUpdated = DateTime.now();
@@ -6655,6 +6663,20 @@ class MeshCoreConnector extends ChangeNotifier {
     final pubkeyFirstByte = path.isNotEmpty
         ? path.last
         : contact.publicKey.first;
+    // Capture the last hop's FULL configured-width prefix (the directly-heard
+    // repeater), not just one byte, so wide-prefix meshes resolve it correctly. (#151)
+    final width = _pathHashByteWidth;
+    final Uint8List pubkeyPrefix;
+    if (path.isNotEmpty) {
+      pubkeyPrefix = Uint8List.fromList(
+        path.sublist(path.length >= width ? path.length - width : 0),
+      );
+    } else {
+      final pk = contact.publicKey;
+      pubkeyPrefix = Uint8List.fromList(
+        pk.length >= width ? pk.sublist(0, width) : pk,
+      );
+    }
 
     _directRepeaters.removeWhere((r) => r.isStale());
 
@@ -6666,7 +6688,7 @@ class MeshCoreConnector extends ChangeNotifier {
     }
 
     final isTracked = _directRepeaters.where(
-      (r) => r.pubkeyFirstByte == pubkeyFirstByte,
+      (r) => listEquals(r.pubkeyPrefix, pubkeyPrefix),
     );
 
     final sortedRepeaters = List<DirectRepeater>.from(_directRepeaters)
@@ -6686,7 +6708,11 @@ class MeshCoreConnector extends ChangeNotifier {
       repeater.update(snr);
     } else if (_directRepeaters.length < 5) {
       _directRepeaters.add(
-        DirectRepeater(pubkeyFirstByte: pubkeyFirstByte, snr: snr),
+        DirectRepeater(
+          pubkeyFirstByte: pubkeyFirstByte,
+          pubkeyPrefix: pubkeyPrefix,
+          snr: snr,
+        ),
       );
     }
     notifyListeners();

lib/widgets/snr_indicator.dart

@@ -1,3 +1,4 @@
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:latlong2/latlong.dart';
 
@@ -10,15 +11,18 @@ import 'signal_ui.dart';
 
 Contact? _getRepeaterPrefixMatchNearLocation(
   List<Contact> contacts,
-  int pubkeyFirstByte, {
+  Uint8List pubkeyPrefix, {
   LatLng? searchPoint,
   bool preferFavorites = false,
 }) {
   final candidates = contacts
       .where(
         (c) =>
-            c.publicKey.isNotEmpty &&
-            c.publicKey.first == pubkeyFirstByte &&
+            c.publicKey.length >= pubkeyPrefix.length &&
+            listEquals(
+              c.publicKey.sublist(0, pubkeyPrefix.length),
+              pubkeyPrefix,
+            ) &&
             (c.type == advTypeRepeater || c.type == advTypeRoom),
       )
       .toList();
@@ -170,7 +174,7 @@ class _SNRIndicatorState extends State<SNRIndicator> {
               ),
               if (directRepeater != null)
                 Text(
-                  '${directRepeaters.length}: ${directRepeater.pubkeyFirstByte.toRadixString(16).padLeft(2, '0')}: ${_formatLastUpdated(directRepeater.lastUpdated)}',
+                  '${directRepeaters.length}: ${directRepeater.prefixHex}: ${_formatLastUpdated(directRepeater.lastUpdated)}',
                   style: TextStyle(
                     fontSize: 12,
                     fontWeight: FontWeight.w500,
@@ -244,7 +248,7 @@ class _SNRIndicatorState extends State<SNRIndicator> {
 
                 final contact = _getRepeaterPrefixMatchNearLocation(
                   allContacts,
-                  repeater.pubkeyFirstByte,
+                  repeater.pubkeyPrefix,
                   searchPoint: selfPoint,
                   preferFavorites: true,
                 );
@@ -255,12 +259,7 @@ class _SNRIndicatorState extends State<SNRIndicator> {
                   children: [
                     ListTile(
                       leading: Icon(snrUi.icon, color: snrUi.color),
-                      title: Text(
-                        name ??
-                            repeater.pubkeyFirstByte
-                                .toRadixString(16)
-                                .padLeft(2, '0'),
-                      ),
+                      title: Text(name ?? repeater.prefixHex),
                       subtitle: Text(
                         'SNR: ${repeater.snr.toStringAsFixed(1)} dB\n${l10n.snrIndicator_lastSeen}: ${_formatLastUpdated(repeater.lastUpdated)}',
                       ),

pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.1.2-rc.1+44
+version: 1.1.2-rc.1+45
 
 environment:
   sdk: ^3.9.2

test/connector/direct_repeater_ranking_test.dart

@@ -1,3 +1,5 @@
+import 'dart:typed_data';
+
 import 'package:flutter_test/flutter_test.dart';
 import 'package:meshcore_open/connector/meshcore_connector.dart';
 
@@ -7,11 +9,13 @@ void main() {
       // 5 dB better SNR, but heard 24 min earlier — signal margin must win.
       final strongOld = DirectRepeater(
         pubkeyFirstByte: 1,
+        pubkeyPrefix: Uint8List.fromList([1]),
         snr: 10.0,
         lastUpdated: DateTime.now().subtract(const Duration(minutes: 25)),
       );
       final weakRecent = DirectRepeater(
         pubkeyFirstByte: 2,
+        pubkeyPrefix: Uint8List.fromList([2]),
         snr: 5.0,
         lastUpdated: DateTime.now().subtract(const Duration(minutes: 1)),
       );
@@ -21,11 +25,13 @@ void main() {
     test('recency breaks ties between equal-SNR repeaters', () {
       final older = DirectRepeater(
         pubkeyFirstByte: 1,
+        pubkeyPrefix: Uint8List.fromList([1]),
         snr: 10.0,
         lastUpdated: DateTime.now().subtract(const Duration(minutes: 20)),
       );
       final newer = DirectRepeater(
         pubkeyFirstByte: 2,
+        pubkeyPrefix: Uint8List.fromList([2]),
         snr: 10.0,
         lastUpdated: DateTime.now().subtract(const Duration(minutes: 1)),
       );
@@ -35,6 +41,7 @@ void main() {
     test('a stale repeater ranks -1', () {
       final stale = DirectRepeater(
         pubkeyFirstByte: 1,
+        pubkeyPrefix: Uint8List.fromList([1]),
         snr: 30.0,
         lastUpdated: DateTime.now().subtract(const Duration(minutes: 31)),
       );
@@ -46,15 +53,37 @@ void main() {
       // stale sentinel (-1) has to sit below every live ranking.
       final weakLive = DirectRepeater(
         pubkeyFirstByte: 1,
+        pubkeyPrefix: Uint8List.fromList([1]),
         snr: -30.0,
         lastUpdated: DateTime.now().subtract(const Duration(minutes: 1)),
       );
       final strongStale = DirectRepeater(
         pubkeyFirstByte: 2,
+        pubkeyPrefix: Uint8List.fromList([2]),
         snr: 30.0,
         lastUpdated: DateTime.now().subtract(const Duration(minutes: 31)),
       );
       expect(weakLive.ranking, greaterThan(strongStale.ranking));
     });
   });
+
+  group('DirectRepeater.prefixHex (#151)', () {
+    test('renders the full configured-width prefix as hex', () {
+      final r = DirectRepeater(
+        pubkeyFirstByte: 0xf4,
+        pubkeyPrefix: Uint8List.fromList([0xf4, 0xab]),
+        snr: 12.0,
+      );
+      expect(r.prefixHex, 'f4ab');
+    });
+
+    test('single-byte prefix renders two hex chars', () {
+      final r = DirectRepeater(
+        pubkeyFirstByte: 0x84,
+        pubkeyPrefix: Uint8List.fromList([0x84]),
+        snr: 12.0,
+      );
+      expect(r.prefixHex, '84');
+    });
+  });
 }