feat: Implement command queue for BLE command handling

- Added BleCommandQueue to manage command serialization and responses in BleCommandSender.
- Updated writeData, writeDataAndWaitForAck, and writeDataAndWaitForResponse methods to utilize the command queue.
- Enhanced BleResponseHandler to complete commands based on responses received from the BLE device.
- Introduced new commands for channel management, including getChannel and setChannel.
- Created LocationTrailLayer and TrailControls widgets for displaying and managing location trails on the map.
- Added PermissionRequestDialog to handle location permission requests on app startup.
- Updated LocationTrackingService to allow GPS tracking without a BLE connection.

lib/models/channel.dart

@@ -0,0 +1,75 @@
+/// Channel model - represents a communication channel
+class Channel {
+  final int index;
+  final String name;
+  final int? flags;
+
+  Channel({
+    required this.index,
+    required this.name,
+    this.flags,
+  });
+
+  /// Display name for the channel
+  /// Returns "Public" for channel 0, otherwise returns the custom name or "Channel N"
+  String get displayName {
+    if (index == 0) {
+      return name.isEmpty ? 'Public' : name;
+    }
+    return name.isEmpty ? 'Channel $index' : name;
+  }
+
+  /// Check if channel is the public channel (index 0)
+  bool get isPublicChannel => index == 0;
+
+  /// Check if channel has a custom name
+  bool get hasCustomName => name.isNotEmpty;
+
+  /// Create from JSON
+  factory Channel.fromJson(Map<String, dynamic> json) {
+    return Channel(
+      index: json['index'] as int,
+      name: json['name'] as String? ?? '',
+      flags: json['flags'] as int?,
+    );
+  }
+
+  /// Convert to JSON
+  Map<String, dynamic> toJson() {
+    return {
+      'index': index,
+      'name': name,
+      'flags': flags,
+    };
+  }
+
+  /// Create a copy with modified fields
+  Channel copyWith({
+    int? index,
+    String? name,
+    int? flags,
+  }) {
+    return Channel(
+      index: index ?? this.index,
+      name: name ?? this.name,
+      flags: flags ?? this.flags,
+    );
+  }
+
+  @override
+  String toString() {
+    return 'Channel(index: $index, name: $name, flags: $flags)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+    return other is Channel &&
+        other.index == index &&
+        other.name == name &&
+        other.flags == flags;
+  }
+
+  @override
+  int get hashCode => Object.hash(index, name, flags);
+}