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/services/ble/protocol.js

@@ -328,7 +328,7 @@ function getWavelengthName(code) {
 
 function getModeStateName(code) {
   var map = {
-    0x00: '空闲', 0x01: '扫描中', 0x02: '护理中',
+    0x00: '空闲', 0x01: '扫描中', 0x02: '使用中',
     0x03: '已暂停', 0x04: '已完成', 0x05: '异常', 0x06: 'OTA升级中'
   }
   return map[code] || '未知'