feat(mp): Phase 1 测试覆盖 + UX 无障碍 — 106 tests PASS + ARIA + focus ring

测试:
- secure-storage: 26 tests (AES 加解密/明文 fallback/迁移/Base64 边界)
- request.ts: 16 tests (扩展 ResponseCache/patientId 隔离/requestUnlimited)
- mock-api: 修复 getCachedPatientId 缺失导致 health 测试失败

UX 无障碍 (10 组件):
- SegmentTabs/DoctorTabBar: role=tablist/tab + aria-selected
- PrimaryButton/SecondaryButton: role=button + aria-disabled/aria-busy
- Loading/LoadingCard: role=status + aria-live=polite
- EmptyState: role=status + aria-live=polite
- ErrorState: role=alert + aria-live=assertive
- TrendChart tooltip: role=tooltip + aria-live=polite
- FormInput: aria-invalid + aria-label

焦点管理:
- 新增 _focus-ring.scss mixin (focus + focus-visible)
- 5 组件 SCSS 应用 focus-ring

apps/miniprogram/src/components/ui/DoctorTabBar/index.scss

@@ -25,6 +25,8 @@
     cursor: pointer;
     -webkit-tap-highlight-color: transparent;
 
+    @include focus-ring;
+
     &--active {
       .doctor-tabbar__icon {
         transform: scale(1.15);

apps/miniprogram/src/components/ui/DoctorTabBar/index.tsx

@@ -31,11 +31,13 @@ export default function DoctorTabBar({ active }: DoctorTabBarProps) {
   };
 
   return (
-    <View className="doctor-tabbar">
+    <View className="doctor-tabbar" role="tablist">
       {DOCTOR_TABS.map((tab) => (
         <View
           key={tab.key}
           className={`doctor-tabbar__item ${tab.key === activeKey ? 'doctor-tabbar__item--active' : ''}`}
+          role="tab"
+          aria-selected={tab.key === activeKey}
           onClick={() => handleTab(tab)}
         >
           <Text className="doctor-tabbar__icon">{tab.key === activeKey ? tab.activeIcon : tab.icon}</Text>

apps/miniprogram/src/components/ui/FormInput/index.scss

@@ -17,6 +17,12 @@
     display: flex;
     align-items: center;
     transition: border-color 0.2s;
+
+    &:focus-within {
+      outline: $focus-ring-width solid $focus-ring-color;
+      outline-offset: $focus-ring-offset;
+      border-color: var(--tk-pri);
+    }
   }
 
   &__control {

apps/miniprogram/src/components/ui/FormInput/index.tsx

@@ -45,6 +45,8 @@ const FormInput: React.FC<FormInputProps> = ({
           type={type}
           maxlength={maxLength}
           disabled={disabled}
+          aria-invalid={!!error}
+          aria-label={label || placeholder}
         />
       </View>
       {error && <Text className='form-input__error'>{error}</Text>}

apps/miniprogram/src/components/ui/LoadingCard/index.tsx

@@ -12,7 +12,7 @@ const LoadingCard: React.FC<LoadingCardProps> = ({
   layout = 'card',
 }) => {
   return (
-    <View className={`loading-card-group loading-card-group--${layout}`}>
+    <View className={`loading-card-group loading-card-group--${layout}`} role="status" aria-label="内容加载中">
       {Array.from({ length: count }, (_, i) => (
         <View key={i} className="loading-card">
           {layout === 'card' && (

apps/miniprogram/src/components/ui/PrimaryButton/index.scss

@@ -29,6 +29,8 @@
     transform: scale(0.98);
   }
 
+  @include focus-ring;
+
   &--disabled {
     opacity: 0.5;
     box-shadow: none;

apps/miniprogram/src/components/ui/PrimaryButton/index.tsx

@@ -28,7 +28,7 @@ const PrimaryButton: React.FC<PrimaryButtonProps> = ({
   ].filter(Boolean).join(' ');
 
   return (
-    <View className={cls} onClick={!disabled && !loading ? onClick : undefined}>
+    <View className={cls} role="button" aria-disabled={disabled} aria-busy={loading} onClick={!disabled && !loading ? onClick : undefined}>
       {loading && <View className='primary-btn__spinner' />}
       <Text className='primary-btn__text'>{children}</Text>
     </View>

apps/miniprogram/src/components/ui/SecondaryButton/index.scss

@@ -18,6 +18,8 @@
     transform: scale(0.98);
   }
 
+  @include focus-ring;
+
   &--disabled {
     opacity: 0.5;
   }

apps/miniprogram/src/components/ui/SecondaryButton/index.tsx

@@ -22,7 +22,7 @@ const SecondaryButton: React.FC<SecondaryButtonProps> = ({
   ].filter(Boolean).join(' ');
 
   return (
-    <View className={cls} onClick={!disabled ? onClick : undefined}>
+    <View className={cls} role="button" aria-disabled={disabled} onClick={!disabled ? onClick : undefined}>
       <Text className='secondary-btn__text'>{children}</Text>
     </View>
   );