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/server/src/shared/providers.ts

@@ -72,6 +72,7 @@ export const PROVIDER_PRESETS: ProviderPreset[] = [
     base_url: 'https://api.kimi.com/coding/v1',
     models: [
       'kimi-for-coding',
+      'kimi-k2.6',
       'kimi-k2.5',
       'kimi-k2-thinking',
       'kimi-k2-turbo-preview',
@@ -84,6 +85,7 @@ export const PROVIDER_PRESETS: ProviderPreset[] = [
     builtin: true,
     base_url: 'https://api.moonshot.cn/v1',
     models: [
+      'kimi-k2.6',
       'kimi-k2.5',
       'kimi-k2-thinking',
       'kimi-k2-turbo-preview',
@@ -247,6 +249,50 @@ export const PROVIDER_PRESETS: ProviderPreset[] = [
     base_url: 'https://api.arcee.ai/v1',
     models: ['trinity-large-thinking', 'trinity-large-preview', 'trinity-mini'],
   },
+  {
+    label: 'Nous Portal',
+    value: 'nous',
+    builtin: true,
+    base_url: 'https://inference-api.nousresearch.com/v1',
+    models: [
+      'moonshotai/kimi-k2.6',
+      'xiaomi/mimo-v2.5-pro',
+      'xiaomi/mimo-v2.5',
+      'anthropic/claude-opus-4.7',
+      'anthropic/claude-opus-4.6',
+      'anthropic/claude-sonnet-4.6',
+      'anthropic/claude-sonnet-4.5',
+      'anthropic/claude-haiku-4.5',
+      'openai/gpt-5.4',
+      'openai/gpt-5.4-mini',
+      'openai/gpt-5.3-codex',
+      'google/gemini-3-pro-preview',
+      'google/gemini-3-flash-preview',
+      'google/gemini-3.1-pro-preview',
+      'google/gemini-3.1-flash-lite-preview',
+      'qwen/qwen3.5-plus-02-15',
+      'qwen/qwen3.5-35b-a3b',
+      'stepfun/step-3.5-flash',
+      'minimax/minimax-m2.7',
+      'minimax/minimax-m2.5',
+      'minimax/minimax-m2.5:free',
+      'z-ai/glm-5.1',
+      'z-ai/glm-5v-turbo',
+      'z-ai/glm-5-turbo',
+      'x-ai/grok-4.20-beta',
+      'nvidia/nemotron-3-super-120b-a12b',
+      'arcee-ai/trinity-large-thinking',
+      'openai/gpt-5.4-pro',
+      'openai/gpt-5.4-nano',
+    ],
+  },
+  {
+    label: 'StepFun',
+    value: 'stepfun',
+    builtin: true,
+    base_url: 'https://api.stepfun.ai/step_plan/v1',
+    models: ['step-3.5-flash', 'step-3.5-flash-2603'],
+  },
   {
     label: 'OpenRouter',
     value: 'openrouter',