feat(settings): use the shared custom dropdown for the AI parsing provider

Swap the native select for CustomSelect so the provider picker matches the rest of the app's styling (dark mode, portal dropdown).

client/src/components/Settings/LlmConnectionSection.tsx

@@ -6,6 +6,7 @@ import { useSettingsStore } from '../../store/settingsStore'
 import type { Settings } from '../../types'
 import Section from './Section'
 import ToggleSwitch from './ToggleSwitch'
+import CustomSelect from '../shared/CustomSelect'
 
 type Provider = NonNullable<Settings['llm_provider']>
 
@@ -76,15 +77,15 @@ export default function LlmConnectionSection(): React.ReactElement {
 
         <div>
           <label className="block text-sm font-medium mb-1.5 text-content-secondary">{t('settings.aiParsing.provider')}</label>
-          <select
+          <CustomSelect
             value={provider}
-            onChange={e => setProvider(e.target.value as Provider)}
-            className="w-full px-3 py-2.5 border rounded-lg text-sm focus:outline-none focus:ring-2 focus:ring-slate-400 border-edge bg-surface-secondary text-content"
-          >
-            <option value="local">{t('settings.aiParsing.providerLocal')}</option>
-            <option value="openai">{t('settings.aiParsing.providerOpenai')}</option>
-            <option value="anthropic">{t('settings.aiParsing.providerAnthropic')}</option>
-          </select>
+            onChange={v => setProvider(v as Provider)}
+            options={[
+              { value: 'local', label: t('settings.aiParsing.providerLocal') },
+              { value: 'openai', label: t('settings.aiParsing.providerOpenai') },
+              { value: 'anthropic', label: t('settings.aiParsing.providerAnthropic') },
+            ]}
+          />
         </div>
 
         <div>