feat(protocol): 更新SPI Link协议至v2版本并优化CAN通信

- 将SPI OTA帧格式升级为SPI Link v2，采用新的帧格式：
  | SOF0 0xA5 | SOF1 0x5A | VER 0x02 | FLAGS | SESSION 4B LE |
  TX_SEQ | ACK_SEQ | CREDIT | TYPE | LEN 2B LE | RSV 2B | PAYLOAD |
  CRC32 4B LE |
- 新增V2_OVERHEAD=20字节开销，APP最大payload为236字节，BOOT为108字节
- 修改帧类型定义：ENTER_BOOT从0xB5合并至0xB0，新增CAN业务类型0xC0~C3
- 更新CAN协议文档，支持SPI Link v2-only模式，调整最大业务payload计算
- 扩展0xC1帧功能，支持双向通信和1Hz主动推送ID快照
- 添加0xC3完整ID快照帧类型，包含seq/rx_count等完整字段
- 更新协议文档中的错误码定义和反馈payload格式

refactor(main): 重构主程序入口并添加CAN反馈任务

- 在main.cpp中添加CAN反馈任务，更新启动流程注释
- 创建createCriticalTask辅助函数，统一关键任务创建逻辑
- 调整SPI初始化顺序，确保CAN反馈任务依赖正确
- 优化错误处理机制，关键任务失败时立即重启
- 将GD32版本探测移至ota_relay任务处理
- 更新版本号至0.3.48，调整编译时间和Git哈希

config: 更新SPI和BLE配置参数

- 添加SPI主机相关配置参数，包括CS GPIO、READY GPIO等引脚定义
- 配置SPI缓冲区大小：APP为256字节，BOOT为128字节
- 更新BLE滑动窗口参数，ACK窗口设为32，数据队列深度为72
- 调整SPI工作队列大小至5120字节，增加任务堆栈监控说明

tools/js/app.js

@@ -36,9 +36,8 @@ import {
 import {
   handleFileSelect, pickFileViaFSAPI, setupDropZone,
   parseIntelHex, isIntelHexText, convertHexFileToBin,
-  processFile, clearFile
+  processFile, clearFile, resumePersistedFirmwareWithGesture
 } from './ota/file-handle.js';
-import { sendSpiFrame, clearSpiFields, updateSpiHint } from './ota/spi.js';
 import { startUpload, verifyEsp32Firmware, restartEsp32 } from './ota/upload-esp32.js';
 import {
   triggerGd32Relay, markGd32OtaUiComplete, stopRelayProgressWatch,
@@ -69,7 +68,14 @@ function isOtaBusyError(status, detail) {
     text.indexOf('系统忙') >= 0;
 }
 function getEspIp() {
-  return document.getElementById('espIp').value.trim() || '192.168.31.127';
+  var el = document.getElementById('espIp');
+  var ip = el && el.value ? el.value.trim() : '';
+  if (!ip) {
+    try { ip = (localStorage.getItem('dcu_esp_ip') || '').trim(); } catch (_) {}
+  }
+  if (!ip) ip = '192.168.31.127';
+  try { localStorage.setItem('dcu_esp_ip', ip); } catch (_) {}
+  return ip;
 }
 function getBaseUrl() {
   return 'http://' + getEspIp();
@@ -77,8 +83,11 @@ function getBaseUrl() {
 function updateUploadButtonLabel() {
   var esp32Btn = document.getElementById('uploadEsp32Btn');
   var gd32Btn = document.getElementById('uploadGd32Btn');
-  if (esp32Btn) esp32Btn.disabled = !window.esp32File || window.isUploading;
-  if (gd32Btn) gd32Btn.disabled = !window.gd32File || window.isUploading;
+  /* 仅 XHR 上传期禁用（isUploading）。校验/中继/重启期允许按钮恢复可点，
+   * startUpload 用 otaSessionActive() 拒绝并发会话。 */
+  var xhrBusy = !!window.isUploading;
+  if (esp32Btn) esp32Btn.disabled = !window.esp32File || xhrBusy;
+  if (gd32Btn) gd32Btn.disabled = !window.gd32File || xhrBusy;
 }
 function resetStageFlow() {
   ['s1', 's2', 's3', 's4', 's5', 's6'].forEach(function (id) {
@@ -163,16 +172,13 @@ window.updateSystemStatusUi = updateSystemStatusUi;
 
 window.handleFileSelect = handleFileSelect;
 window.pickFileViaFSAPI = pickFileViaFSAPI;
+window.resumePersistedFirmwareWithGesture = resumePersistedFirmwareWithGesture;
 window.parseIntelHex = parseIntelHex;
 window.isIntelHexText = isIntelHexText;
 window.convertHexFileToBin = convertHexFileToBin;
 window.processFile = processFile;
 window.clearFile = clearFile;
 
-window.sendSpiFrame = sendSpiFrame;
-window.clearSpiFields = clearSpiFields;
-window.updateSpiHint = updateSpiHint;
-
 window.startUpload = startUpload;
 window.verifyEsp32Firmware = verifyEsp32Firmware;
 window.restartEsp32 = restartEsp32;
@@ -223,10 +229,6 @@ window.isOtaBusyError = isOtaBusyError;
 // ==================== 顶层副作用（原 app.js 末尾的初始化） ====================
 setupDropZone('uploadZoneEsp32', 'esp32');
 setupDropZone('uploadZoneGd32', 'gd32');
-var spiTypeEl = document.getElementById('spiType');
-var spiDataEl = document.getElementById('spiData');
-if (spiTypeEl) spiTypeEl.addEventListener('input', updateSpiHint);
-if (spiDataEl) spiDataEl.addEventListener('input', updateSpiHint);
 
 // 启动轮询（必须在所有模块加载完成、window.OtaSessionState 已挂载后调用，
 //   否则 polling.js 的 scheduleStatusPoll 会因 window.OtaSessionState 未定义而抛 TypeError）
@@ -235,7 +237,12 @@ startPolling();
 // IP 输入变化时清零失败计数并立即刷新状态
 var ipInput = document.getElementById('espIp');
 if (ipInput) {
+  try {
+    var savedIp = localStorage.getItem('dcu_esp_ip');
+    if (savedIp && savedIp.trim()) ipInput.value = savedIp.trim();
+  } catch (_) {}
   ipInput.addEventListener('change', function () {
+    try { localStorage.setItem('dcu_esp_ip', ipInput.value.trim() || '192.168.31.127'); } catch (_) {}
     window.consecutivePollFailures = 0;
     addLog('I', '系统', 'IP 已修改，重新启动轮询...');
     if (!window.statusPollInFlight) {
@@ -248,5 +255,4 @@ if (ipInput) {
 setTimeout(function () {
   updateUploadButtonLabel();
   addLog('I', '系统', '控制台初始化完成，等待固件文件...');
-  updateSpiHint();
 }, 500);