feat: sync treatment record at start (10min), update on early stop

- Treatment start immediately syncs record with full 10min duration
- Early stop re-syncs with actual elapsed time (upsert by session_id)
- treatment-done page uses same session_id from treating page

miniprogram/pages/treatment-done/treatment-done.js

@@ -55,8 +55,8 @@ Page({
     http.post('/api/v1/treatment/sync', {
       session_id: self.data.sessionId,
       device_id: self._deviceId || '',
-      start_time: new Date(Date.now() - self.data.duration).toISOString(),
-      end_time: new Date().toISOString(),
+      start_time: treatment.start_time || new Date(Date.now() - self.data.duration).toISOString(),
+      end_time: treatment.end_time || new Date().toISOString(),
       regions: self.data.regions,
       total_duration_ms: self.data.duration,
       mode: self.data.mode,