feat(checkin): open reference-parity details modal from signed buttons

- Rebuild checkin details modal HTML 1:1 with reference theme:
  colorful header c-blue, user card (points/level), daily reward
  card and 7-day continuous mini cards
- Signed entry buttons (header dropdown, user-card badge, user
  center) become clickable checkin-details-link modal triggers
  instead of disabled buttons
- Swap data-signin-btn to details link in place after successful
  signin (reference .initiate-checkin replacement behavior)
- Add aksrt-checkin-details-modal runtime shell (modal-mini 400px)
- Remove dead code: legacy lite modal, admin-ajax details handler,
  /signin/history route, signin calendar; rebuild public bundles
- Update contract tests to the new checkin modal contract

tests/widget-system/post-visual-contract.test.cjs

@@ -460,11 +460,14 @@ test('profile routes load versioned leaf styles and keep dialogs hidden initiall
   assert.match(userCenterCreditsCss, /#panel-credits\.dashboard-panel\s*\{[^}]*background:\s*transparent;[^}]*box-shadow:\s*none;/);
   assert.match(userCenterCreditsCss, /\.uc-asset-tabs\s*\{[^}]*background:\s*var\(--surface-1,\s*#fff\);[^}]*border:[^;}]+;[^}]*box-shadow:[^;}]+;/);
   assert.doesNotMatch(profileCredits, /credits-signin\.php|data-aksrt-signin-calendar/);
-  // 签到日历只存在于签到弹窗（src/Credits/Signin.php + enhancements2.js），
-  // 用户中心里的孤儿渲染器已整包移除。
+  // 签到详情弹窗为参考主题 1:1 结构（src/Credits/Signin.php），日历已随
+  // 旧版 lite 弹窗一并移除；用户中心里的孤儿渲染器也已整包移除。
   assert.equal(fs.existsSync(path.join(root, 'inc/helpers/user-center-renderers/credits-signin.php')), false);
   assert.doesNotMatch(userCenterCreditsCss + read('assets/css/frontend/enhancements/components/custom-amount.css'), /uc-signin-calendar/);
-  assert.match(read('src/Credits/Signin.php'), /data-aksrt-signin-calendar/);
+  const signinModalHtml = read('src/Credits/Signin.php');
+  assert.match(signinModalHtml, /modal-colorful-header colorful-bg c-blue/);
+  assert.match(signinModalHtml, /checkin-mini-box/);
+  assert.doesNotMatch(signinModalHtml, /data-aksrt-signin-calendar/);
   assert.match(profileOrders, /data-aksrt-orders-filter-panel hidden/);
   assert.doesNotMatch(profileOrders, /\$_GET|add_query_arg|name="order_(?:status|type|number|page)"/);
   assert.match(profileOrders, /data-aksrt-orders-filter-panel hidden[\s\S]*?aksrt-orders-page__status-filters[\s\S]*?aksrt-orders-page__type-filters/);