[ruby] Optimise Architecture of App

[hayat01sh1da]

1. Overview

This PR removes the only RuboCop override in ruby/.rubocop.yml and completes the project's RBS inline coverage.
The config excluded **/test/**/* from Style/Documentation because the sub-app test directories (e.g. fizzbuzz/test/) are not matched by RuboCop's default top-level test/**/* exclusion, so six test classes were flagged as missing top-level documentation.
Instead of keeping the exclusion, each of the six test classes now carries a one-line documentation comment, and the one test file that lacked the # rbs_inline: enabled magic comment (letter_matching_inspection/test/application_test.rb) received it, so every test file now participates in signature generation.

2. Key Changes & Differences

File	Before	After	Changes & Differences
ruby/.rubocop.yml	Style/Documentation: Exclude: '**/test/**/*'	Plugins + AllCops only	Patch deleted.
Six ruby/**/test/*_test.rb files	No class comment	One-line documentation comment per test class	Resolves Style/Documentation in code.
ruby/letter_matching_inspection/test/application_test.rb	No # rbs_inline: enabled magic comment	Magic comment added	The only test file previously outside rbs-inline's scope.
ruby/sig/generated/**	No sig for the letter-matching test; other test sigs lacked the new doc comments	letter_matching_inspection/test/application_test.rbs generated for the first time; five test sigs refreshed	Regenerated with rbs-inline --output sig/generated/ ..

3. Summary

Comment-only changes plus regenerated signatures; no runtime behaviour is affected.
Verified with RuboCop 1.88.1 (16 files inspected, no offenses detected) and rbs-inline 0.14.0 regeneration.

Branch commits (newest first):

• 4fad39d Articulate RBS inline types and regenerate signatures
• 2b58093 Remove Style/Documentation RuboCop patch
• 12de45d Add documentation comments to test classes

4. References

• Ruby Style Guide
• Style/Documentation
• rbs-inline

[hayat01sh1da]