feat: add StepFun and Nous Portal provider support (#140)

- Add StepFun provider (API key auth, STEPFUN_API_KEY)
- Add Nous Portal provider with full OAuth device code flow
  (device code request → poll for token → mint agent key → save to auth.json)
- Add NousLoginModal component for OAuth UI (user code display + verification link)
- Update ProviderFormModal to handle Nous OAuth flow (hide API key fields)
- Add nous-auth backend controller and routes
- Update PROVIDER_ENV_MAP with stepfun and nous entries
- Add i18n translations for Nous OAuth in all 8 locales

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

packages/client/src/api/hermes/nous-auth.ts

@@ -0,0 +1,29 @@
+import { request } from '../client'
+
+export interface NousStartResult {
+  session_id: string
+  user_code: string
+  verification_url: string
+  expires_in: number
+}
+
+export interface NousPollResult {
+  status: 'pending' | 'approved' | 'denied' | 'expired' | 'error'
+  error: string | null
+}
+
+export interface NousStatusResult {
+  authenticated: boolean
+}
+
+export async function startNousLogin(): Promise<NousStartResult> {
+  return request<NousStartResult>('/api/hermes/auth/nous/start', { method: 'POST' })
+}
+
+export async function pollNousLogin(sessionId: string): Promise<NousPollResult> {
+  return request<NousPollResult>(`/api/hermes/auth/nous/poll/${sessionId}`)
+}
+
+export async function getNousAuthStatus(): Promise<NousStatusResult> {
+  return request<NousStatusResult>('/api/hermes/auth/nous/status')
+}