feat(mistral-ai): update model YAMLs [bot]

[harshiv-26]

Auto-generated by poc-agent for provider mistral-ai.

---

Note

Low Risk
Changes only update provider YAML metadata (declared features/modalities, costs, and sources) and do not touch runtime code paths. Risk is limited to misconfiguration affecting model selection or capability/cost reporting.

Overview
Updates labs-leanstral-2603 metadata to advertise assistant_prefill support and add code to declared input/output modalities.

Adds explicit per-token costs for mistral-vibe-cli-fast and includes an additional documentation/source link.

^{Reviewed by Cursor Bugbot for commit d1babcc. Bugbot is set up for automated code reviews on this repo. Configure here.}

[github-actions]

/test-models

[harshiv-26]

Gateway test results

• Total: 5
• Passed: 4
• Failed: 0
• Validation failed: 0
• Errored: 0
• Skipped: 1
• Success rate: 100.0%

Provider	Model	Scenarios
mistral-ai	labs-leanstral-2603	skipped: skip-check
mistral-ai	mistral-vibe-cli-fast	success: tool-call, params:stream, params, tool-call:stream

Skipped (1)

mistral-ai/labs-leanstral-2603 — skip-check (skipped)

Skip reason:

Experimental Mistral Labs model; not generally available