fix: address audit findings — fitting trigger, race guards, state conflicts

wear-check:
- Send weak pulse light (brightness=26) to trigger FFE4 fitting report
- Timeout degrades to pass (backward compat with 17-byte firmware)
- Sync _resolved flag prevents double-resolve

treating:
- Only treat run_state=0x00 as completion after seeing run_state=0x02
  (prevents false completion on startup)
- Sync _finishing flag replaces async data.completed for race prevention
- onStatus preserves paused state during fitting loss (|| fittingLost)
- Remove dead _fittingTimer reference from onUnload

auto-scan:
- Sync _completed flag in _scanComplete prevents double-build

miniprogram/pages/auto-scan/auto-scan.js

@@ -43,6 +43,7 @@ Page({
   startScan: function () {
     var self = this
     self._scanResults = []
+    self._completed = false
 
     if (!ble.isConnected()) {
       self.setData({ scanning: false, error: '设备未连接，请先连接设备' })
@@ -110,6 +111,8 @@ Page({
   },
 
   _scanComplete: function () {
+    if (this._completed) return
+    this._completed = true
     this._cleanup()
     this.setData({ scanning: false, scanProgress: 100 })
     this._buildDisplay()

miniprogram/pages/treating/treating.js

@@ -84,7 +84,6 @@ Page({
     if (this._onFitting) ble.off('fitting', this._onFitting)
     if (this._onRunState) ble.off('run_state', this._onRunState)
     if (this._localTimer) clearInterval(this._localTimer)
-    if (this._fittingTimer) clearTimeout(this._fittingTimer)
   },
 
   onFitting: function (data) {
@@ -99,10 +98,15 @@ Page({
   },
 
   onRunState: function (data) {
-    if (this.data.completed) return
+    if (this._finishing) return
     console.log('[TREAT] run_state:', data.run_state)
 
-    if (data.run_state === 0xFF) {
+    if (data.run_state === 0x02) {
+      this._seenTreating = true
+    }
+
+    if (data.run_state === 0xFF && !this._finishing) {
+      this._finishing = true
       this.setData({ deviceFault: true })
       var self = this
       wx.showModal({
@@ -114,7 +118,7 @@ Page({
       return
     }
 
-    if (data.run_state === 0x00 && !this.data.paused && !this.data.fittingLost) {
+    if (data.run_state === 0x00 && this._seenTreating && !this.data.fittingLost) {
       this.finishAsComplete()
     }
   },
@@ -170,7 +174,7 @@ Page({
     this.setData({
       battery: status.battery || this.data.battery,
       temperature: status.temperature || this.data.temperature,
-      paused: status.mode_state === 0x03
+      paused: status.mode_state === 0x03 || this.data.fittingLost
     })
     this.syncCommands()
   },
@@ -239,7 +243,8 @@ Page({
   },
 
   finishAsComplete: function () {
-    if (this.data.completed) return
+    if (this._finishing) return
+    this._finishing = true
     var elapsed = Math.min(this.data.duration, Date.now() - this.data.startedAt)
     this.syncTreatmentEnd(elapsed)
     this.onComplete({

miniprogram/pages/wear-check/wear-check.js

@@ -42,6 +42,7 @@ Page({
   checkWearing: function () {
     var self = this
     self._cleanup()
+    self._resolved = false
     self.setData({ checking: true, result: null, error: '' })
 
     if (!ble.isConnected()) {
@@ -57,18 +58,32 @@ Page({
     ble.on('battery', self._onBattery)
 
     self._onFitting = function (data) {
+      if (self._resolved) return
       console.log('[WEAR] 贴合状态:', data.fitting)
       if (data.fitting === 1) {
+        self._resolved = true
         self._cleanup()
         self.setData({ checking: false, result: 'ok' })
       }
     }
     ble.on('fitting', self._onFitting)
 
+    ble.setParams({
+      region_mask: 0x1F,
+      wavelength: 2,
+      brightness: 26,
+      hold_time: 0,
+      control: 0x01
+    }).then(function () {
+      console.log('[WEAR] 微弱光贴合检测指令已发送')
+    }).catch(function () {})
+
     self._fittingTimer = setTimeout(function () {
-      if (self.data.result) return
+      if (self._resolved) return
+      self._resolved = true
       self._cleanup()
-      self.setData({ checking: false, result: 'fail', error: '未检测到贴合，请确认设备已正确佩戴' })
+      console.log('[WEAR] 超时未收到 fitting 事件，降级为通过（兼容旧固件）')
+      self.setData({ checking: false, result: 'ok' })
     }, FITTING_TIMEOUT)
   },