feat: switch firmware updates to bootloader OTA

lib/model/shifter_types.dart

@@ -18,8 +18,6 @@ const String universalShifterDfuControlCharacteristicUuid =
     '0993826f-0ee4-4b37-9614-d13ecba40008';
 const String universalShifterDfuDataCharacteristicUuid =
     '0993826f-0ee4-4b37-9614-d13ecba40009';
-const String universalShifterDfuAckCharacteristicUuid =
-    '0993826f-0ee4-4b37-9614-d13ecba4000a';
 const String universalShifterDfuStatusCharacteristicUuid =
     '0993826f-0ee4-4b37-9614-d13ecba4000a';
 const String ftmsServiceUuid = '00001826-0000-1000-8000-00805f9b34fb';
@@ -41,15 +39,12 @@ const int universalShifterDfuOpcodeAbort = 0x03;
 const int universalShifterDfuOpcodeGetStatus = 0x04;
 
 const int universalShifterDfuFrameSizeBytes = 64;
-const int universalShifterDfuFramePayloadSizeBytes = 63;
 const int universalShifterBootloaderDfuDataHeaderSizeBytes = 9;
 const int universalShifterBootloaderDfuMaxPayloadSizeBytes =
     universalShifterDfuFrameSizeBytes -
         universalShifterBootloaderDfuDataHeaderSizeBytes;
 const int universalShifterBootloaderDfuStatusSizeBytes = 6;
 const int universalShifterAttWriteOverheadBytes = 3;
-const int universalShifterDfuMinimumMtu =
-    universalShifterDfuFrameSizeBytes + universalShifterAttWriteOverheadBytes;
 const int universalShifterDfuPreferredMtu = 128;
 
 const int universalShifterDfuAppStart = 0x00030000;
@@ -78,9 +73,14 @@ const int trainerScanDeviceFlagConnectable = 0x08;
 enum DfuUpdateState {
   idle,
   starting,
-  waitingForAck,
+  enteringBootloader,
+  connectingBootloader,
+  waitingForStatus,
+  erasing,
   transferring,
   finishing,
+  rebooting,
+  verifying,
   completed,
   aborted,
   failed,
@@ -119,18 +119,20 @@ class DfuUpdateProgress {
     required this.state,
     required this.totalBytes,
     required this.sentBytes,
-    required this.lastAckedSequence,
+    required this.expectedOffset,
     required this.sessionId,
     required this.flags,
+    this.bootloaderStatus,
     this.errorMessage,
   });
 
   final DfuUpdateState state;
   final int totalBytes;
   final int sentBytes;
-  final int lastAckedSequence;
+  final int expectedOffset;
   final int sessionId;
   final DfuUpdateFlags flags;
+  final DfuBootloaderStatus? bootloaderStatus;
   final String? errorMessage;
 
   double get fractionComplete {
@@ -191,61 +193,6 @@ class DfuBootloaderStatus {
   bool get isOk => code == DfuBootloaderStatusCode.ok;
 }
 
-enum DfuPreflightFailureReason {
-  deviceNotConnected,
-  wrongConnectedDevice,
-  mtuRequestFailed,
-  mtuTooLow,
-}
-
-class DfuPreflightResult {
-  const DfuPreflightResult._({
-    required this.requestedMtu,
-    required this.requiredMtu,
-    required this.negotiatedMtu,
-    required this.failureReason,
-    required this.message,
-  });
-
-  final int requestedMtu;
-  final int requiredMtu;
-  final int? negotiatedMtu;
-  final DfuPreflightFailureReason? failureReason;
-  final String? message;
-
-  bool get canStart => failureReason == null;
-
-  static DfuPreflightResult ready({
-    required int requestedMtu,
-    required int negotiatedMtu,
-    int requiredMtu = universalShifterDfuMinimumMtu,
-  }) {
-    return DfuPreflightResult._(
-      requestedMtu: requestedMtu,
-      requiredMtu: requiredMtu,
-      negotiatedMtu: negotiatedMtu,
-      failureReason: null,
-      message: null,
-    );
-  }
-
-  static DfuPreflightResult failed({
-    required int requestedMtu,
-    required DfuPreflightFailureReason failureReason,
-    required String message,
-    int requiredMtu = universalShifterDfuMinimumMtu,
-    int? negotiatedMtu,
-  }) {
-    return DfuPreflightResult._(
-      requestedMtu: requestedMtu,
-      requiredMtu: requiredMtu,
-      negotiatedMtu: negotiatedMtu,
-      failureReason: failureReason,
-      message: message,
-    );
-  }
-}
-
 class ShifterErrorInfo {
   const ShifterErrorInfo({
     required this.code,