fix: remap locations for unused disable directives

[xbinaryx]

Prerequisites checklist

• I have read the contributing guidelines.

AI acknowledgment

• I did not use AI to generate this PR.
• (If the above is not checked) I have reviewed the AI-generated content before submitting.

What is the purpose of this pull request?

This PR enables the reporting of unused directive comments (such as <!-- eslint-disable no-console -->) in Markdown files. When reportUnusedDisableDirectives is enabled, ESLint flags these configuration comments if they do not actively suppress any rules. Because the Markdown processor prepends these comments to the generated code, they fall outside the block boundaries. Previously, the processor returned null for these messages, causing ESLint to skip them. This PR intercepts unused directive reports and correctly maps them back to their absolute line, column, and autofix offsets in the Markdown source.

What changes did you make? (Give an overview)

• Changed comments from an array of strings to objects that track original source location position.
• Updated the processor to identify unused directive messages and intercept them for remapping.
• Added test coverage validating correct remapping and autofix offsets across single and multiple comment scenarios.

Related Issues

Fixes #115

Is there anything you'd like reviewers to focus on?

[DMartens]

Changes LGTM, thanks. Leaving open for lumir.