fix(frontend): route every user-center points label through the custom currency name

后台「积分配置 → 自定义货币名称」改名后，用户中心仍有大量硬编码
「积分」：做任务赚积分 / 购买积分 / 签到领积分、积分记录 / 积分任务、
每日可免费获取 XX 积分、我的积分、积分+1、创作中心积分收益等。

get_currency_name() 早已存在且可用，问题只是这些文案没有走它。
本PR 全部替换，无双路、无迁移：

服务端渲染（用户中心 renderers）
- credits-balance.php：购买/做任务赚/签到领 + 整个购买弹窗
- profile-credits.php：积分记录 / 积分任务 页签
- credits-points-tasks.php：每日上限三态与空态
- sidebar-creator.php / profile-creator.php：积分收益
- transfer-modal.php：积分转账提示
- Signin.php：签到详情弹窗（我的积分 / 奖励 tooltip / 积分+N）
- VipServiceModal.php：我的积分 / 积分兑换会员
- download-permission-card.php：购买价格

客户端渲染（JS 无法调用 PHP，注入 currencyName 到 aksrtData）
- signin.js：签到状态行「已签到 N 天 +1」
- credits.js：转账标题/金额标签 + 购买提示 toast
- cms-download.js：积分不足视图、我的积分 入口、余额不足文案
- pay-vip.js：积分兑换会员入口（优先 catalog.currency_name）
- order-center.js：订单行单位回退

契约测试同步改为断言模板构造而非死字符串，并新增两例：
改名后跟随、未注入时回退「积分」。

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/widget-system/signin-runtime.test.cjs

@@ -64,7 +64,7 @@ function deferred() {
   return { promise, resolve, reject };
 }
 
-function setup({ buttons = [makeButton('btn uc-header__signin-btn', '签到')], captchaSignin = false, today = Promise.resolve({ ok: true, status: 200, json: { enabled: true, signed: false, streak: 1, reward_if_signin: 2 } }), signin = Promise.resolve({ ok: true, status: 200, json: { message: '签到成功，积分 +2', balance: 12 } }), captchaRun } = {}) {
+function setup({ buttons = [makeButton('btn uc-header__signin-btn', '签到')], captchaSignin = false, currencyName = '', today = Promise.resolve({ ok: true, status: 200, json: { enabled: true, signed: false, streak: 1, reward_if_signin: 2 } }), signin = Promise.resolve({ ok: true, status: 200, json: { message: '签到成功，积分 +2', balance: 12 } }), captchaRun } = {}) {
   const calls = [];
   const notices = [];
   const balance = { textContent: '10', title: '10' };
@@ -84,7 +84,7 @@ function setup({ buttons = [makeButton('btn uc-header__signin-btn', '签到')],
   };
   const jq = { off() { return this; }, on(event, callback) { listeners[event] = callback; return this; } };
   const window = {
-    aksrtData: { captchaSignin, signinDetailsUrl: '/wp-json/aksrt/v1/signin/details' },
+    aksrtData: { captchaSignin, signinDetailsUrl: '/wp-json/aksrt/v1/signin/details', currencyName },
     AksrtModalRuntime: { open: (...args) => modals.push(args), openRemote: (...args) => modals.push(args) },
     AksrtRequest: { request(endpoint, options) { calls.push({ endpoint, options }); return endpoint === '/signin/today' ? today : signin; } },
   };
@@ -99,6 +99,32 @@ function setup({ buttons = [makeButton('btn uc-header__signin-btn', '签到')],
 
 const settle = () => new Promise((resolve) => setImmediate(resolve));
 
+test('status line follows the custom currency name instead of hardcoding 积分', async () => {
+  // 后台「积分配置 → 自定义货币名称」改名后，签到状态行必须跟着变，
+  // 否则这里仍显示「积分」。
+  const button = makeButton('btn', '签到');
+  const success = deferred();
+  const h = setup({ buttons: [button], currencyName: '金币', signin: success.promise });
+  await settle();
+  button.click();
+  await settle();
+  success.resolve({ ok: true, status: 200, json: { message: '签到成功', balance: 12, streak: 3, reward: 2 } });
+  await settle();
+  assert.equal(h.status.innerHTML, '已签到 <strong>3</strong> 天 +2 金币');
+});
+
+test('status line falls back to 积分 when no custom currency name is injected', async () => {
+  const button = makeButton('btn', '签到');
+  const success = deferred();
+  const h = setup({ buttons: [button], signin: success.promise });
+  await settle();
+  button.click();
+  await settle();
+  success.resolve({ ok: true, status: 200, json: { message: '签到成功', balance: 12, streak: 3, reward: 2 } });
+  await settle();
+  assert.equal(h.status.innerHTML, '已签到 <strong>3</strong> 天 +2 积分');
+});
+
 test('uses reference loading, success toast, and replaces all entry points with detail links', async () => {
   const first = makeButton('img-badge jb-yellow', '签到', '<i class="fa far fa-calendar-check ml3 mr6"></i>');
   const second = makeButton('btn uc-header__signin-btn', '签到', '<i class="fa fa-calendar-check"></i>', '今日已签到');
@@ -136,7 +162,8 @@ test('uses reference loading, success toast, and replaces all entry points with
   assert.equal(h.calls.filter((call) => call.endpoint === '/signin/today').length, 1, 'success does not issue another status request');
   assert.equal(h.modals.length, 0, 'success does not open a modal');
   assert.equal(h.balance.textContent, '12');
-  assert.equal(h.status.innerHTML, '已签到 <strong>2</strong> 天 +2');
+  // 状态行在奖励数值后追加自定义货币名称（未注入时回退「积分」）。
+  assert.equal(h.status.innerHTML, '已签到 <strong>2</strong> 天 +2 积分');
 });
 
 test('keeps the profile done style on its replacement link', async () => {
@@ -228,7 +255,7 @@ test('ignores an old today response after successful sign-in', async () => {
   await settle();
   assert.ok(button.replaced, 'success replaced the action with the details link');
   assert.match(button.replaced.innerHTML, /已签到/);
-  assert.equal(h.status.innerHTML, '已签到 <strong>3</strong> 天 +2');
+  assert.equal(h.status.innerHTML, '已签到 <strong>3</strong> 天 +2 积分');
 });
 
 test('leaves a disabled sign-in feature disabled without turning it into a signed state', async () => {