accept map on generate object

[DanielAlegriaLino]

Description

Fix incorrect @spec for generate_object/4 and generate_object!/4 in ReqLLM.Generation. The spec was missing map() as a valid type for the object_schema parameter, even though the implementation fully supports raw JSON Schema maps.

Type of Change

• Bug fix (non-breaking change fixing an issue)
• New feature (non-breaking change adding functionality)
• Breaking change (fix or feature causing existing functionality to change)
• Documentation update

Breaking Changes

N/A - This is a non-breaking fix that corrects the typespec to match existing behavior.

Testing

• Tests pass (mix test)
• Quality checks pass (mix quality)

Checklist

• My code follows the project's style guidelines
• I have updated the documentation accordingly
• I have added tests that prove my fix/feature works
• All new and existing tests pass
• My commits follow conventional commit format
• I have NOT edited CHANGELOG.md (it is auto-generated by git_ops)

Related Issues

Closes #

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Details:

The @spec specified keyword() | Zoi.Type.t() but Schema.compile/1 accepts keyword() | map() | struct(), and the documentation explicitly shows passing raw JSON Schema maps:

array_schema = %{"type" => "array", "items" => person_schema}
ReqLLM.generate_object("openai:gpt-4o", "Generate 3 heroes", array_schema)