feat(grok): 视频改走 Grok Console 并新增图片模型

- grok 视频/图片统一走 console.x.ai：sso 换 DPoP 短期 token，绕开 grok.com 的 statsig 反爬

- 新增 grok-image：不带参考图走 /v1/images/generations，带图自动走 quality 上游 + /v1/images/edits

- grok 额度改本地写死 图5/视频2，成功各扣一次，两份归零直接判死，无恢复时间

- 视频渲染预算统一 20 分钟（adobe/runway/grok/custom）

- 删除参考图人脸打码（facemask + onnxruntime 依赖 + 前台开关）

README.en.md

@@ -133,7 +133,7 @@ It's more than an API proxy: it ships with **credit billing, CDK top-ups, referr
 | **Adobe Firefly** | firefly-image-5 · firefly-gpt-image-2 · flux-kontext-max · nano-banana-2 · nano-banana-pro · firefly-video · firefly-ray · gemini-veo31 | Image / Video |
 | **OpenAI** | gpt-image-2 | Image |
 | **Runway** | runway-gen4-turbo · runway-nano-banana-2 (Nano Banana 2) · runway-nano-banana-pro (Nano Banana Pro) | Video / Image |
-| **Grok (grok.com)** | grok-video (imagine text/image-to-video) | Video |
+| **Grok (console.x.ai)** | grok-video (imagine text/image-to-video), grok-image / grok-image-quality (imagine text/image-to-image) | Video / Image |
 | **Leonardo.ai** | seedream-4.5 | Image |
 | **Krea.ai** | flux-klein-2 | Image |
 | **Imagine.art** | imagine-1.5 · imagine-1.5pro | Image |
@@ -245,7 +245,7 @@ backend/                       Backend source (Go)
 │   │   ├── adobe/             Adobe Firefly (tls-client fingerprint)
 │   │   ├── chatgpt/           OpenAI (incl. PoW / turnstile)
 │   │   ├── runway/            Runway video + Nano Banana image
-│   │   ├── grok/              Grok (grok.com, spoofed statsig, video)
+│   │   ├── grok/              Grok (console.x.ai DPoP, video / image; account state via grok.com)
 │   │   ├── leonardo/          Leonardo
 │   │   ├── krea/              Krea
 │   │   ├── imagine/           Imagine.art