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/app.json

@@ -21,7 +21,7 @@
   ],
   "window": {
     "navigationBarBackgroundColor": "#ffffff",
-    "navigationBarTitleText": "光子美容仪",
+    "navigationBarTitleText": "智美",
     "navigationBarTextStyle": "black",
     "backgroundColor": "#f5f5f5"
   },
@@ -47,7 +47,7 @@
   },
   "permission": {
     "scope.bluetooth": {
-      "desc": "用于连接光子美容仪设备"
+      "desc": "用于连接智能设备"
     },
     "scope.userLocation": {
       "desc": "蓝牙连接需要位置权限"