feat: add Codex OAuth login and fix channel config display

- Add OpenAI Codex Device Code Flow login (backend polling + frontend modal)
- Codex provider integrated into preset dropdown (hides URL/API key fields)
- Sync provider model catalogs with Hermes system
- Fix channel config not displaying on first visit (wait for data load)
- Fix sidebar model list not refreshing after adding provider
- Add autocomplete="off" to API key input to prevent browser autofill

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/client/src/views/hermes/ChannelsView.vue

@@ -21,7 +21,7 @@ onMounted(() => {
 
     <div class="channels-content">
       <NSpin :show="settingsStore.loading || settingsStore.saving" size="large" :description="t('common.loading')">
-        <PlatformSettings />
+        <PlatformSettings v-if="!settingsStore.loading" />
       </NSpin>
     </div>
   </div>