refactor: restructure entire project for human maintainability

Server:
- Add Express framework, replace custom router/request parser
- Create DAO layer (12 files) centralizing all 73 SQL queries
- Rewrite 7 route files as thin Express controllers calling DAOs
- Add SCF-to-Express adapter (lib/serverless.js)
- Add auth middleware (middleware/auth.js)
- Remove dead code from lib/auth.js

Admin console:
- Extract DataTable component (table + pagination)
- Extract ConfirmModal component (modal + form styles)
- Create listMixin for paginated list pages
- Move form styles to common.css for slot compatibility
- Refactor device + subscription pages as examples

Miniprogram:
- Split 734-line BLE monolith into 4 focused modules
  (protocol, connection, commands, barrel index)
- Create API module (utils/api.js) with named functions
- Create page utilities (utils/page.js)
- Refactor index + profile pages to use API module

miniprogram/services/ble/commands.js

@@ -0,0 +1,187 @@
+// BLE commands: writing commands and high-level device operations
+
+var protocol = require('./protocol')
+var connection = require('./connection')
+
+var _cmdSeq = 0
+var _pendingAcks = {}
+
+function nextSeq() {
+  _cmdSeq = (_cmdSeq + 1) % 256
+  return _cmdSeq
+}
+
+function getPendingAcks() {
+  return _pendingAcks
+}
+
+function clearPendingAcks() {
+  _pendingAcks = {}
+}
+
+// --- low-level write ---
+
+function writeCommand(type, payload) {
+  return new Promise(function (resolve, reject) {
+    if (!connection.isConnected()) {
+      reject({ error_code: 0x0C, error_msg: 'ERR_BLE_DISCONNECTED' })
+      return
+    }
+    var chars = connection.getChars()
+    if (!chars.command) {
+      reject({ error_code: 0xFF, error_msg: 'command characteristic not found' })
+      return
+    }
+
+    var seq = nextSeq()
+    var payloadWithSeq = (payload || []).concat([seq])
+    var buffer = protocol.buildFrame(type, payloadWithSeq)
+
+    _pendingAcks[seq] = { resolve: resolve, reject: reject }
+
+    setTimeout(function () {
+      if (_pendingAcks[seq]) {
+        _pendingAcks[seq].reject({ error_code: 0xFF, error_msg: 'ACK timeout' })
+        delete _pendingAcks[seq]
+      }
+    }, 5000)
+
+    var deviceId = connection.getDeviceId()
+    wx.writeBLECharacteristicValue({
+      deviceId: deviceId,
+      serviceId: chars.command.serviceId,
+      characteristicId: chars.command.uuid,
+      value: buffer,
+      success: function () {},
+      fail: function () {
+        delete _pendingAcks[seq]
+        reject({ error_code: 0x0C, error_msg: 'ERR_BLE_DISCONNECTED' })
+      }
+    })
+  })
+}
+
+function writeCommandWithRetry(type, payload, maxRetries) {
+  if (maxRetries === undefined) maxRetries = 3
+  var attempt = 0
+  function tryOnce() {
+    attempt++
+    return writeCommand(type, payload).catch(function (err) {
+      if (err && err.error_code === 0x0C) {
+        return Promise.reject(err)
+      }
+      if (attempt >= maxRetries) {
+        return Promise.reject(err)
+      }
+      return new Promise(function (resolve) {
+        setTimeout(resolve, 500)
+      }).then(function () {
+        return tryOnce()
+      })
+    })
+  }
+  return tryOnce()
+}
+
+// --- high-level commands ---
+
+function readDeviceInfo() {
+  return new Promise(function (resolve, reject) {
+    var chars = connection.getChars()
+    var deviceId = connection.getDeviceId()
+    if (!connection.isConnected() || !chars.deviceInfo) {
+      reject({ msg: '设备未连接或特征值未就绪' })
+      return
+    }
+    wx.readBLECharacteristicValue({
+      deviceId: deviceId,
+      serviceId: chars.deviceInfo.serviceId,
+      characteristicId: chars.deviceInfo.uuid,
+      success: function () {},
+      fail: function () { reject({ msg: '读取设备信息失败' }) }
+    })
+
+    var handler = function (res) {
+      if (res.characteristicId.toUpperCase().indexOf(protocol.CHAR.DEVICE_INFO) !== -1) {
+        wx.offBLECharacteristicValueChange(handler)
+        var bytes = protocol.bufferToBytes(res.value)
+        if (bytes.length >= 14) {
+          resolve({
+            hw_version: (bytes[0] << 8) | bytes[1],
+            fw_version: (bytes[2] << 8) | bytes[3],
+            device_type: (bytes[4] << 8) | bytes[5],
+            device_id: protocol.bytesToHex(bytes.slice(6, 14))
+          })
+        } else {
+          reject({ msg: '设备信息格式错误' })
+        }
+      }
+    }
+    wx.onBLECharacteristicValueChange(handler)
+  })
+}
+
+function setParams(options) {
+  var regionMask = options.region_mask || protocol.REGION.FULL_FACE
+  var wavelength = options.wavelength || protocol.WAVELENGTH.R
+  var brightness = options.brightness || 200
+  var durationMs = options.duration_ms || 600000
+  var mode = options.mode !== undefined ? options.mode : protocol.TREAT_MODE.NORMAL
+
+  var payload = [
+    regionMask,
+    wavelength,
+    brightness,
+    protocol.uint32ToBytes(durationMs),
+    mode
+  ].reduce(function (a, b) {
+    return a.concat(Array.isArray(b) ? b : [b])
+  }, [])
+
+  return writeCommandWithRetry(protocol.CMD.SET_PARAMS, payload)
+}
+
+function startTreatment(regionMask) {
+  var mask = regionMask || protocol.REGION.FULL_FACE
+  return writeCommandWithRetry(protocol.CMD.START, [mask])
+}
+
+function stopTreatment() {
+  return writeCommandWithRetry(protocol.CMD.STOP, [])
+}
+
+function queryStatus() {
+  return writeCommandWithRetry(protocol.CMD.QUERY_STATUS, [])
+}
+
+function bindDevice(userId, bindToken) {
+  var userBytes = protocol.hexToBytes(userId)
+  var tokenBytes = protocol.hexToBytes(bindToken)
+  var ts = Math.floor(Date.now() / 1000)
+  var tsBytes = protocol.uint32ToBytes(ts)
+
+  var payload = [0x01].concat(userBytes).concat(tokenBytes).concat(tsBytes)
+  return writeCommandWithRetry(protocol.CMD.BIND, payload)
+}
+
+function unbindDevice(userId) {
+  var userBytes = protocol.hexToBytes(userId)
+  var payload = [0x02].concat(userBytes)
+  return writeCommandWithRetry(protocol.CMD.UNBIND, payload)
+}
+
+module.exports = {
+  getPendingAcks: getPendingAcks,
+  clearPendingAcks: clearPendingAcks,
+
+  writeCommand: writeCommand,
+  writeCommandWithRetry: writeCommandWithRetry,
+
+  readDeviceInfo: readDeviceInfo,
+  setParams: setParams,
+  startTreatment: startTreatment,
+  stopTreatment: stopTreatment,
+  queryStatus: queryStatus,
+  bindDevice: bindDevice,
+  unbindDevice: unbindDevice
+}