feat: 新增客户端问题主动上报与控制台问题汇总功能

1. 客户端 (ticketmachine.lua): 修改 showAlert 支持详细错误并主动上报，使用 pcall 包装主循环捕获 Fatal Error 并上报。
2. 服务端 (data.js, api.js): 增加 issues 数据表，提供 /report_issue 和 /issues 接口。
3. 控制台 (index.html, index.js): 添加“问题汇总”菜单及界面状态管理。

ticketmachine.lua

@@ -327,6 +327,19 @@ local function enqueueTicketUpload(ticketData)
   return false
 end
 
+local function reportIssue(errMsg, detail)
+  local url = API_BASE .. '/report_issue'
+  local payload = {
+    device = currentDeviceId(),
+    machine_id = currentDeviceId(),
+    station_code = state.stationCode or CURRENT_STATION_CODE,
+    error_msg = tostring(errMsg or ''),
+    detail = tostring(detail or ''),
+    ts = (os.epoch and os.epoch('utc')) or (os.time() * 1000)
+  }
+  postJSONResult(url, payload)
+end
+
 -- ###########################
 -- Peripheral discovery
 -- ###########################
@@ -1286,14 +1299,22 @@ local function renderConfirmCancel()
   addButton(bx+4+bw, by+4, 'NO', bw, 1, {colors.green, colors.white}, function() ui_cancel_confirmed = false; ui_cancel_request = false end)
 end
 
-local function showAlert(msg)
+local function showAlert(msg, detail)
+  if detail then
+    reportIssue(msg, detail)
+  end
   local boxW, boxH = math.max(24, math.min(32, w-4)), 6
   local bx, by = math.floor((w-boxW)/2)+1, math.floor((h-boxH)/2)+1
   termDev.setBackgroundColor(colors.gray)
   for i=0,boxH-1 do termDev.setCursorPos(bx, by+i); termDev.write(string.rep(' ', boxW)) end
-  msg = tostring(msg or '')
-  if #msg > boxW-4 then msg = msg:sub(1, boxW-4) end
-  termDev.setTextColor(colors.white); termDev.setCursorPos(bx+2, by+2); termDev.write(msg)
+  local displayMsg = tostring(msg or '')
+  if #displayMsg > boxW-4 then displayMsg = displayMsg:sub(1, boxW-4) end
+  termDev.setTextColor(colors.white); termDev.setCursorPos(bx+2, by+2); termDev.write(displayMsg)
+  if detail then
+    local displayDetail = tostring(detail)
+    if #displayDetail > boxW-4 then displayDetail = displayDetail:sub(1, boxW-4) end
+    termDev.setCursorPos(bx+2, by+3); termDev.write(displayDetail)
+  end
   Buttons = {}
   addButton(bx+math.floor((boxW-6)/2), by+4, 'OK', 6, 1, {colors.green, colors.white}, function() end)
   waitButtons()
@@ -1815,7 +1836,7 @@ local function showTerminal()
         invalidUntil = os.epoch('utc') + 1500
         sel = nil
         state.terminal = nil
-        showAlert('Same station')
+        showAlert('Same station', 'Dep and Term are identical')
       else
         state.terminal = sel
       end
@@ -2073,7 +2094,7 @@ local function showOrderAndAudio()
     else
       local unit = computeCost(state.departure or '', state.terminal or '', state.trainType or 'Local')
       if not unit then
-        showAlert('No route')
+        showAlert('No route', 'Cannot find fare path')
         state.page = 'terminal'
         return
       end
@@ -2084,7 +2105,7 @@ local function showOrderAndAudio()
   end
 
   if state.productMode ~= 'card' and state.trainType ~= 'single' and sameLogicalStation(state.departure, state.terminal) then
-    showAlert('Same station')
+    showAlert('Same station', 'Cannot purchase to same station')
     state.page = state.voucher_code and 'online' or 'terminal'
     return
   end
@@ -2097,7 +2118,7 @@ local function showOrderAndAudio()
   local function confirmAction()
     if processing or confirmed then return end
     if state.productMode ~= 'card' and sameLogicalStation(state.departure, state.terminal) then
-      showAlert('Same station')
+      showAlert('Same station', 'Dep and Term are identical on confirm')
       if render then render() end
       return
     end
@@ -2411,7 +2432,7 @@ local function showDone()
     local issueError = tostring(issueMethod or 'ticket_issue_failed')
     print('Ticket issue failed: ' .. issueError)
     _G.TICKET_MACHINE_LAST_TICKET.ticket_issue_error = issueError
-    showAlert('Ticket issue failed')
+    showAlert('Ticket issue failed', issueError)
     resetTicketFlow()
     state.page = 'home'
     return
@@ -2608,4 +2629,12 @@ local function mainPageLoop()
   end
 end
 
-parallel.waitForAny(mainPageLoop, backgroundSyncTask, backgroundTicketUploadTask, backgroundPeripheralTask)
+local function safeMain()
+  local ok, err = pcall(parallel.waitForAny, mainPageLoop, backgroundSyncTask, backgroundTicketUploadTask, backgroundPeripheralTask)
+  if not ok then
+    reportIssue("Fatal Error", tostring(err))
+    error(err)
+  end
+end
+
+safeMain()