docs(core): add YARD documentation for core dispatcher

[Ganesh-abc]

Summary

This PR adds YARD documentation to the Core/Modules Command Dispatcher.

This change improves code readability and developer understanding without modifying any runtime behavior.

This PR is a focused split from #21146 to simplify review.

Verification

• Start msfconsole
• Run help to confirm Core dispatcher loads correctly
• Run search type:exploit to confirm Modules dispatcher works
• Run ruby -c <file> → Syntax OK
• Run bundle exec rubocop <file> → 0 offenses
• Verified no functional changes introduced

Notes

This PR only updates documentation and formatting. No functional changes were made.

[github-actions]

Thanks for your pull request! As part of our landing process, we manually verify that all modules work as expected.

We've added the additional-testing-required label to indicate that additional testing is required before this pull request can be merged.
For maintainers, this means visiting here.