Expose Azure gpt-5.2/gpt-5.3 xhigh reasoning effort + CLI alias

[dzianisv]

Problem

Azure Codex deployments accept reasoningEffort: xhigh, but opencode only exposes low/medium/high for Azure. That prevents selecting xhigh in the CLI/UI. Also, users expect --reasoning-effort to be an alias for --variant on opencode run.

Expected

• Azure GPT-5.2/5.3 models expose xhigh variant.
• opencode run --reasoning-effort maps to variant.

Notes

A local eval indicates Azure accepts the request but does not return reasoning parts/tokens; see PR for details.

[github-actions]

This issue doesn't fully meet our contributing guidelines.

What needs to be fixed:

• Feature requests must use the feature request template, which requires a verification checkbox confirming the feature doesn't already exist.
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Please edit this issue to address the above within 2 hours, or it will be automatically closed.

---

This issue might be a duplicate of existing issues. Please check:

• GPT-5 models on Azure and reasoning_effort argument #12121: GPT-5 models on Azure and reasoning_effort argument (covers Azure + reasoning_effort support)
• Azure models fail due to reasoning_effort being sent even with --variant none #12113: Azure models fail due to reasoning_effort being sent even with --variant none (related Azure reasoning_effort handling)

If you believe this was flagged incorrectly, please let a maintainer know.

[github-actions]

This issue has been automatically closed because it was not updated to meet our contributing guidelines within the 2-hour window.

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