feat(providers): add AICraft OpenAI-compatible provider template

[BX166]

Summary

Adds AICraft (aicraftapi.com) as an OpenAI-compatible provider setup template, following the same descriptor-row pattern as SenseNova, Baseten, Groq, Cerebras, and Command Code.

• AICRAFT_TEMPLATE_ID = "aicraft"
• AICRAFT_BASE_URL = "https://aicraftapi.com/v1"
• AICRAFT_DEFAULT_MODEL = "claude-4.6-sonnet"
• AICRAFT_API_KEY_ENV = "AICRAFT_API_KEY"

Changes

• Four new consts plus one ProviderSetupApply::Compatible descriptor row, inserted before the unpublished agnes entry.
• Updated settings_value_names_fillable_then_unpublished to include aicraft in the fillable list.
• Added an aicraft entry to hosted_openai_compat_hosts_are_templates_not_enum_variants.
• Updated the module header comment.

Test plan

• The two touched unit tests (settings_value_names_fillable_then_unpublished, hosted_openai_compat_hosts_are_templates_not_enum_variants) are expected to pass under the existing crates/config test suite.

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[github-actions]

Thanks @BX166 for taking the time to contribute.

This repository is observing a maintainer-managed PR intake gate in dry-run mode, so this pull request is staying open. This note helps maintainers prepare the allowlist before any enforcement is considered.

Please read CONTRIBUTING.md for the expected contribution shape. A maintainer can grant recurring PR access by commenting /lgtm on a pull request.

[BX166]

Addressed the review: AICraft is now documented in docs/PROVIDERS.md alongside the other compatible templates. The new row sits between Command Code and Agnes:

| AICraft | compatible | ```https://aicraftapi.com/v1``` | ```claude-4.6-sonnet``` | ```AICRAFT_API_KEY``` |

This satisfies every_compatible_template_is_documented_for_operators (display name, base URL, and API key env are all present).