fix: 登录页白底+渐变边框/胶囊加大/底部提示/今日健康优化/发送按钮蓝紫渐变

- 登录页：输入框白底+渐变紫蓝外框，去掉focus内框；登录按钮白底紫字；协议勾选白底
- 首页胶囊：适老化加大(内边距14x8/字号15/图标17/圆角18)
- 欢迎卡片底部提示：各智能体专属引导文案，字号加大颜色加深
- 今日健康卡片：健康指标改一行总结(异常提醒/正常显示)；用药显示具体药品名+状态
- 发送按钮：蓝→紫渐变
- 设置页菜单：白色卡片+圆角16+轻阴影
- IP改localhost：adb reverse解决IP变动问题
- 服药打卡快捷按钮：改为跳转打卡页，不再一键全打

health_app/lib/pages/home/home_page.dart

@@ -232,7 +232,11 @@ class _HomePageState extends ConsumerState<HomePage> {
             width: 40, height: 40,
             margin: EdgeInsets.only(bottom: _pickedImagePath != null ? 0 : 4),
             decoration: BoxDecoration(
-              color: AppColors.blueMeasure,
+              gradient: const LinearGradient(
+                colors: [AppColors.blueMeasure, AppColors.primary],
+                begin: Alignment.topLeft,
+                end: Alignment.bottomRight,
+              ),
               borderRadius: BorderRadius.circular(20),
             ),
             child: const Icon(LucideIcons.send, size: 20, color: Colors.white),