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/api/hermes/codex-auth.ts

@@ -0,0 +1,30 @@
+import { request } from '../client'
+
+export interface CodexStartResult {
+  session_id: string
+  user_code: string
+  verification_url: string
+  expires_in: number
+}
+
+export interface CodexPollResult {
+  status: 'pending' | 'approved' | 'expired' | 'error'
+  error: string | null
+}
+
+export interface CodexStatusResult {
+  authenticated: boolean
+  last_refresh?: string
+}
+
+export async function startCodexLogin(): Promise<CodexStartResult> {
+  return request<CodexStartResult>('/api/hermes/auth/codex/start', { method: 'POST' })
+}
+
+export async function pollCodexLogin(sessionId: string): Promise<CodexPollResult> {
+  return request<CodexPollResult>(`/api/hermes/auth/codex/poll/${sessionId}`)
+}
+
+export async function getCodexAuthStatus(): Promise<CodexStatusResult> {
+  return request<CodexStatusResult>('/api/hermes/auth/codex/status')
+}