feat: 健康仪表盘配色调整 + 登录页品牌升级 + iOS 配置 + 隐私文案修订 + 文档清理

## UI 配色
- 健康仪表盘: 背景从蓝紫粉三色渐变改为 #4FACFE 纯色蓝, 白字清晰不抢眼
- app_colors / app_design_tokens / app_theme: 配色体系微调
- 多个 widget 和页面跟随配色更新(health_drawer/admin_drawer/doctor_drawer/enterprise_widgets 等)

## 登录页品牌升级
- 新增品牌素材: drawer_background_v2 / login_background_v2 / health_login_character_transparent
- login_page 重构, 接入新品牌视觉
- app.dart 启动流程调整

## iOS / Android 配置
- Info.plist: 权限描述调整
- AppIcon / LaunchImage: 资源更新
- AndroidManifest: 权限微调

## 隐私文案修订
- privacy.html: 蓝牙设备描述调整为"标准蓝牙血压服务", 移除未上线设备类型表述
- terms.html: 移除"在线医生咨询"相关条款, 服务范围收窄

## 通知中心
- notification_center_page: 重构通知项布局

## 其他
- 删除已完成的计划/spec 文档(ui-system-first-pass / apple-sign-in / secondary-page-color-refresh / notification-preferences-design / ui-design-system)
- 新增 native_navigation_test
- 新增 HANDOFF 交接文档
- home_message_order_test 更新
- .gitignore 调整

health_app/lib/pages/auth/login_page.dart

@@ -19,7 +19,7 @@ class LoginPage extends ConsumerStatefulWidget {
 }
 
 class _LoginPageState extends ConsumerState<LoginPage> {
-  static const _loginBg = 'assets/branding/login_background_v1.png';
+  static const _loginBg = 'assets/branding/login_background_v2.png';
   static const _loginActionGradient = AppColors.primaryGradient;
 
   void _openStaticText(String type) {
@@ -220,7 +220,7 @@ class _LoginPageState extends ConsumerState<LoginPage> {
                 textAlign: TextAlign.center,
                 style: TextStyle(
                   fontSize: 21,
-                  fontWeight: FontWeight.w900,
+                  fontWeight: FontWeight.w700,
                   color: AppColors.textPrimary,
                   letterSpacing: 0,
                 ),
@@ -303,7 +303,7 @@ class _LoginPageState extends ConsumerState<LoginPage> {
                           style: TextStyle(
                             color: Colors.white,
                             fontSize: 16,
-                            fontWeight: FontWeight.w900,
+                            fontWeight: FontWeight.w700,
                           ),
                         ),
                       ),
@@ -350,7 +350,7 @@ class _LoginPageState extends ConsumerState<LoginPage> {
                         '选择健康服务医生',
                         style: TextStyle(
                           fontSize: 18,
-                          fontWeight: FontWeight.w800,
+                          fontWeight: FontWeight.w600,
                           color: AppColors.textPrimary,
                         ),
                       ),
@@ -438,10 +438,12 @@ class _LoginPageState extends ConsumerState<LoginPage> {
       body: Stack(
         children: [
           Positioned.fill(
-            child: Image.asset(
-              _loginBg,
-              fit: BoxFit.cover,
-              alignment: Alignment.topCenter,
+            child: RepaintBoundary(
+              child: Image.asset(
+                _loginBg,
+                fit: BoxFit.cover,
+                alignment: Alignment.topCenter,
+              ),
             ),
           ),
           Positioned.fill(
@@ -460,16 +462,13 @@ class _LoginPageState extends ConsumerState<LoginPage> {
               ),
             ),
           ),
-          AnimatedPadding(
-            duration: const Duration(milliseconds: 180),
-            curve: Curves.easeOutCubic,
-            padding: EdgeInsets.only(
-              bottom: MediaQuery.viewInsetsOf(context).bottom,
-            ),
+          _LoginKeyboardLift(
             child: SafeArea(
               child: LayoutBuilder(
                 builder: (context, constraints) {
                   return SingleChildScrollView(
+                    keyboardDismissBehavior:
+                        ScrollViewKeyboardDismissBehavior.onDrag,
                     padding: const EdgeInsets.fromLTRB(20, 22, 20, 24),
                     child: ConstrainedBox(
                       constraints: BoxConstraints(
@@ -589,7 +588,7 @@ class _LoginPageState extends ConsumerState<LoginPage> {
                                           _isLogin ? '没有账号？去注册' : '已有账号？去登录',
                                           style: const TextStyle(
                                             fontSize: 14,
-                                            fontWeight: FontWeight.w800,
+                                            fontWeight: FontWeight.w600,
                                           ),
                                         ),
                                       ),
@@ -613,6 +612,23 @@ class _LoginPageState extends ConsumerState<LoginPage> {
   }
 }
 
+class _LoginKeyboardLift extends StatelessWidget {
+  final Widget child;
+
+  const _LoginKeyboardLift({required this.child});
+
+  @override
+  Widget build(BuildContext context) {
+    final keyboardHeight = MediaQuery.viewInsetsOf(context).bottom;
+    final lift = (keyboardHeight * 0.42).clamp(0.0, 150.0);
+    return Transform.translate(
+      offset: Offset(0, -lift),
+      transformHitTests: true,
+      child: RepaintBoundary(child: child),
+    );
+  }
+}
+
 class _LoginHero extends StatelessWidget {
   const _LoginHero();
 
@@ -626,7 +642,7 @@ class _LoginHero extends StatelessWidget {
           '小脉健康',
           style: TextStyle(
             fontSize: 28,
-            fontWeight: FontWeight.w900,
+            fontWeight: FontWeight.w700,
             color: AppColors.textPrimary,
             letterSpacing: 0,
           ),
@@ -676,26 +692,11 @@ class _BrandMark extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return SizedBox(
-      width: 108,
-      height: 108,
-      child: Container(
-        clipBehavior: Clip.antiAlias,
-        decoration: BoxDecoration(
-          color: Colors.white.withValues(alpha: 0.72),
-          shape: BoxShape.circle,
-          border: Border.all(color: Colors.white.withValues(alpha: 0.86)),
-          boxShadow: [
-            BoxShadow(
-              color: AppColors.primary.withValues(alpha: 0.10),
-              blurRadius: 20,
-              offset: const Offset(0, 8),
-            ),
-          ],
-        ),
-        child: Image.asset(
-          'assets/branding/health_icon_master.png',
-          fit: BoxFit.cover,
-        ),
+      width: 116,
+      height: 116,
+      child: Image.asset(
+        'assets/branding/health_login_character_transparent.png',
+        fit: BoxFit.contain,
       ),
     );
   }
@@ -981,7 +982,7 @@ class _PrimaryButton extends StatelessWidget {
                 style: const TextStyle(
                   fontSize: 17,
                   color: Colors.white,
-                  fontWeight: FontWeight.w800,
+                  fontWeight: FontWeight.w600,
                 ),
               ),
       ),