Clean up resolveIndexedAccessMethod

[mcmire]

Explanation

resolveIndexedAccessMethod still contains istanbul ignore comments. Most of these are unnecessary, and the logic actually ought to be tested.

This commit cleans up these istanbul ignore comments, and also adds new ones to clarify the existing logic. It also renames resolveIndexedAccessMethod to findClassMethodDeclaration so that it's easier to understand the purpose of this function at a glance.

References

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Low Risk
Documentation extraction only; behavior is clarified and covered by new tests, with no runtime product surface change.

Overview
Refactors messenger action handler resolution in platform-api-docs extraction: resolveIndexedAccessMethod is renamed to findClassMethodDeclaration, with clearer guards, inline examples, and removal of istanbul ignore coverage skips on paths that are now meant to run in production.

Adds five tests that assert when Class['method'] cannot be resolved (object-literal type, keyof, numeric index, namespace-qualified class, missing method), docs still show the raw handler type text instead of failing or inventing a signature. Successful resolution behavior is unchanged; only naming, comments, and test coverage for fallbacks differ.

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