fix: remove all medical device terms from user-facing text

Replace '光子美容仪' with '智美'/'智能面膜'/'我的设备' throughout.
Replace '护理' with '使用' in all UI text.
Replace '皮肤' with '检测'/'智能' where applicable.
Replace 🌸 with 💎 for brand identity.
Internal code (variable names, API paths, file names) unchanged.

miniprogram/pages/treatment-done/treatment-done.json

@@ -1,4 +1,4 @@
 {
   "navigationStyle": "custom",
-  "navigationBarTitleText": "护理完成"
+  "navigationBarTitleText": "使用完成"
 }