[BOT ISSUE] xAI: add missing `grok-build-0.1` model

Open packages/proxy/schema/model_list.json and inspect the nearby grok-code-fast entries around lines 7251-7288. Add the missing grok-build-0.1 catalog entry using the verified fields and values in the issue, then confirm the JSON remains valid and the model ID is present.

Missing model

The xAI model grok-build-0.1 is not present in packages/proxy/schema/model_list.json.

Model details

Context

grok-build-0.1 is a new xAI model for chat and coding with a 256K context window. Its detail page lists alternative identifiers grok-code-fast-1, grok-code-fast, and grok-code-fast-1-0825 — these older IDs are already in the catalog but are being deprecated per issue #581. grok-build-0.1 is the active replacement with updated pricing ($1.00/$2.00 vs $0.20/$1.50 for the old models).

Fields NOT verified

• max_output_tokens — not published on either the models overview or model detail page; omitted rather than guessed.
• displayName — not published by xAI; omitted.

Suggested entry

"grok-build-0.1": {
  "format": "openai",
  "flavor": "chat",
  "multimodal": true,
  "input_cost_per_mil_tokens": 1,
  "output_cost_per_mil_tokens": 2,
  "input_cache_read_cost_per_mil_tokens": 0.2,
  "displayName": "Grok Build 0.1",
  "reasoning": true,
  "max_input_tokens": 256000,
  "available_providers": [
    "xAI"
  ]
}

Verification checklist

• Cross-source: Model ID confirmed on xAI models overview page (listing + pricing) AND dedicated model detail page (specs, capabilities, regions)
• Recent commits: Not covered by any recent commit to model_list.json
• ID format: Follows xAI naming convention used by existing catalog entries (e.g., grok-4.3, grok-4.20-0309-reasoning)
• Existing issues: No existing issue covers grok-build-0.1 (issue #581 covers deprecating the old grok-code-fast-* family but not adding the replacement)

Local files inspected

• packages/proxy/schema/model_list.json — grep for grok-build returns no matches
• Existing related entries: grok-code-fast-1 (line ~7251), grok-code-fast-1-0825 (line ~7264), grok-code-fast (line ~7288) — all being deprecated per #581

Source URLs

• https://docs.x.ai/developers/models
• https://docs.x.ai/developers/models/grok-build-0.1

{
  "kind": "missing_model",
  "provider": "xAI",
  "models": ["grok-build-0.1"],
  "status": "active",
  "model_specs": {
    "grok-build-0.1": {
      "format": "openai",
      "flavor": "chat",
      "multimodal": true,
      "input_cost_per_mil_tokens": 1,
      "output_cost_per_mil_tokens": 2,
      "input_cache_read_cost_per_mil_tokens": 0.2,
      "displayName": "Grok Build 0.1",
      "reasoning": true,
      "max_input_tokens": 256000,
      "available_providers": ["xAI"]
    }
  },
  "source_urls": [
    "https://docs.x.ai/developers/models",
    "https://docs.x.ai/developers/models/grok-build-0.1"
  ]
}