feat(frontend): Phase 5d-ii — settings General tab

Ports the panel/general partial (the largest single tab) — six
collapse panels: General, Notifications, Certificates, External
traffic webhook, Date and time, LDAP.

- GeneralTab.vue receives the reactive AllSetting via props and binds
  fields directly with v-model:value; SettingsPage stays the sole
  fetch/save owner.
- remarkModel/remarkSeparator surfaced as computed v-models that
  read+write the underlying single-string field (legacy stores them
  packed as <separator><orderedKeys>, e.g. "-ieo").
- LDAP inbound-tags select binds to a CSV ↔ array computed; inbound
  options come from /panel/api/inbounds/list on mount.
- Language select stays cookie-based via LanguageManager and reloads
  on change — same UX as legacy.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/pages/settings/SettingsPage.vue

@@ -14,6 +14,7 @@ import { theme as themeState } from '@/composables/useTheme.js';
 import { useMediaQuery } from '@/composables/useMediaQuery.js';
 import AppSidebar from '@/components/AppSidebar.vue';
 import { useAllSetting } from './useAllSetting.js';
+import GeneralTab from './GeneralTab.vue';
 
 const antdThemeConfig = computed(() => ({
   algorithm: themeState.isDark ? antdTheme.darkAlgorithm : antdTheme.defaultAlgorithm,
@@ -206,7 +207,7 @@ const alertVisible = ref(true);
                         <SettingOutlined />
                         <span>Panel</span>
                       </template>
-                      <a-empty description="General — coming in 5d-ii" />
+                      <GeneralTab :all-setting="allSetting" />
                     </a-tab-pane>
                     <a-tab-pane key="2" class="tab-pane">
                       <template #tab>