功能(充值弹层): 会员周期切换支持键盘方向键

- 月付/年付 radiogroup 原先无 roving tabindex，方向键无法移动选项
- 复用 resolveRovingIndex 与 ref，方向键同步移动选中与焦点；锁定时不响应方向键
- 补一条周期切换键盘导航测试

packages/shared/src/components/PlatformProfileRechargeModal/index.test.tsx

@@ -197,6 +197,52 @@ describe('PlatformProfileRechargeModal', () => {
     );
   });
 
+  test('周期切换按钮支持方向键与 roving tabindex', async () => {
+    const user = userEvent.setup();
+
+    render(
+      <PlatformProfileRechargeModal
+        center={{
+          mudPointBalance: buildMudPointBalance(29),
+          membership: buildNormalMembership(),
+          pointProducts: buildPointProducts(),
+          membershipPlans: [STARTER_PLAN, PLUS_PLAN],
+          latestOrder: null,
+          hasPointsRecharged: false,
+        }}
+        isLoading={false}
+        error={null}
+        submittingProductId={null}
+        nativePayment={null}
+        membershipQuote={null}
+        isLoadingMembershipQuote={false}
+        membershipQuoteError={null}
+        onClose={vi.fn()}
+        onRetry={vi.fn()}
+        onBuy={vi.fn()}
+        onRequestMembershipQuote={vi.fn()}
+        onSubmitMembershipCheckout={vi.fn()}
+        onConfirmNativePayment={vi.fn()}
+        onCloseNativePayment={vi.fn()}
+      />,
+    );
+
+    const group = screen.getByRole('radiogroup', { name: '付费周期' });
+    const monthly = within(group).getByRole('radio', { name: '月付' });
+    const yearly = within(group).getByRole('radio', { name: '年付' });
+    expect(monthly.getAttribute('tabindex')).toBe('0');
+    expect(yearly.getAttribute('tabindex')).toBe('-1');
+
+    monthly.focus();
+    await user.keyboard('{ArrowRight}');
+
+    expect(yearly.getAttribute('aria-checked')).toBe('true');
+    expect(monthly.getAttribute('aria-checked')).toBe('false');
+    expect(yearly.getAttribute('tabindex')).toBe('0');
+    expect(monthly.getAttribute('tabindex')).toBe('-1');
+    expect(document.activeElement).toBe(yearly);
+  });
+
   test('requests the server quote and shows the upgrade amount', async () => {
     const user = userEvent.setup();
     const onRequestMembershipQuote = vi.fn();

packages/shared/src/components/PlatformProfileRechargeModal/index.tsx

@@ -641,6 +641,8 @@ function PlatformMembershipCycleSwitch({
     { id: 'monthly', label: '月付' },
     { id: 'yearly', label: '年付' },
   ];
+  // 与泥点档位一致：roving tabindex + 方向键移动焦点，保证键盘可切换周期。
+  const optionRefs = useRef<Record<string, HTMLButtonElement | null>>({});
 
   return (
     <div className="flex items-center justify-between gap-3">
@@ -648,15 +650,41 @@ function PlatformMembershipCycleSwitch({
         role="radiogroup"
         aria-label="付费周期"
         className="platform-subpanel flex gap-1 rounded-full p-1"
+        onKeyDown={(event) => {
+          if (locked) {
+            return;
+          }
+          const currentIndex = options.findIndex(
+            (option) => option.id === cycleKind,
+          );
+          const nextIndex = resolveRovingIndex(
+            event.key,
+            currentIndex,
+            options.length,
+          );
+          if (nextIndex === null) {
+            return;
+          }
+          event.preventDefault();
+          const nextOption = options[nextIndex];
+          if (nextOption) {
+            onChange(nextOption.id);
+            optionRefs.current[nextOption.id]?.focus();
+          }
+        }}
       >
         {options.map((option) => {
           const selected = option.id === cycleKind;
           return (
             <button
               key={option.id}
+              ref={(node) => {
+                optionRefs.current[option.id] = node;
+              }}
               type="button"
               role="radio"
               aria-checked={selected}
+              tabIndex={selected ? 0 : -1}
               disabled={locked && !selected}
               onClick={() => onChange(option.id)}
               className={joinClassNames(