feat(billing): guide parents to recharge the child account

tests/unit/point-wallet.test.tsx

@@ -27,14 +27,31 @@ describe('permanent point wallet', () => {
     expect(dialog).toHaveTextContent('永久有效');
     expect(screen.queryByText(/重置卡|升级订阅|本周剩余/)).not.toBeInTheDocument();
   });
-  it('shows youth own precision and shared availability without enabling recharge', async () => {
+  it('honors unavailable recharge without asking the user to change account identity', async () => {
     api.summary.mockResolvedValue(billingSummary({ can_recharge: false, payment_configured: false, own_points: permanentBalance({ can_recharge: false }), points: permanentBalance({ total: null, used: null, reserved: null, total_remaining: null, family_shared: true, entitlement_source: 'family_owner', shared_available: false, can_recharge: false }) }));
     render(<PointWallet />); await screen.findByText('75 点');
     expect(screen.getByText(/AI 编程使用共享点数/)).toHaveTextContent('已用尽');
     fireEvent.click(screen.getByTestId('sidebar-point-wallet-open'));
-    await screen.findByText(/仅家长身份可以充值/);
+    await screen.findByText(/当前账号暂不能充值，请在社区账户页查看原因或联系支持/);
+    expect(screen.queryByText(/仅家长身份可以充值/)).not.toBeInTheDocument();
     expect(screen.getByRole('button', { name: /500 点\s*¥10.00/ })).toBeDisabled();
   });
+  it('recharges the displayed child account while leaving shared funding selected', async () => {
+    api.summary.mockResolvedValue(billingSummary({ points: permanentBalance({ total: null, used: null, reserved: null, total_remaining: null, family_shared: true, entitlement_source: 'shared_group', shared_available: true, can_recharge: false }) }));
+    render(<PointWallet accountName="小麦" accountUsername="child-account" />);
+    await screen.findByText('75 点');
+    fireEvent.click(screen.getByTestId('sidebar-point-wallet-open'));
+    const dialog = screen.getByTestId('point-wallet-dialog');
+    expect(screen.getByTestId('point-recharge-recipient')).toHaveTextContent('充值到：小麦（child-account）');
+    expect(dialog).toHaveTextContent('请由家长登录孩子的账号完成付款');
+    expect(dialog).toHaveTextContent('充值不会自动切换付款来源');
+    const buy = within(dialog).getByRole('button', { name: /500 点\s*¥10.00/ });
+    await waitFor(() => expect(buy).toBeEnabled());
+    fireEvent.click(buy);
+    await screen.findByTestId('point-recharge-checkout');
+    expect(api.create).toHaveBeenCalledWith('recharge-10', expect.any(String));
+    expect(api.external).not.toHaveBeenCalled();
+  });
   it('does not mistake the family payer’s own shared wallet for an exhausted external wallet', async () => {
     api.summary.mockResolvedValue(billingSummary({ points: permanentBalance({ family_shared: true, entitlement_source: 'shared_group' }) }));
     await openWallet();