Add RuboCop for code standardization

[cardmagic]

Summary

Add RuboCop with rubocop-minitest for consistent code style and automated linting in CI.

Changes

• Add rubocop and rubocop-minitest gems
• Create .rubocop.yml with project-specific configuration
• Auto-correct 151 style offenses
• Add respond_to_missing? to Bayes class (fixes RuboCop warning)
• Add lint job to CI workflow (runs on Ruby 3.3)

Configuration Highlights

• Exclude legacy bin/ and install.rb files
• Exclude complex algorithm files from metrics checks (SVD, LSI)
• Single quotes for strings
• Minitest best practices enabled

Files Excluded from Metrics

Some files contain complex mathematical algorithms that exceed standard metrics. These are tracked in #60 for future refactoring:

• lib/classifier/extensions/vector.rb (SVD algorithm)
• lib/classifier/lsi/content_node.rb (vector operations)
• lib/classifier/lsi.rb (index building)

CI

New lint job runs RuboCop on every push/PR.

Fixes #56

[Copilot]

Pull request overview

This PR adds RuboCop with rubocop-minitest for consistent code style and automated linting in CI. The changes include adding RuboCop gems, configuring style rules, auto-correcting 151 style offenses across test and library files, and adding a lint job to the CI workflow.

Key changes:

• Added RuboCop configuration excluding legacy files and complex algorithms from metrics checks
• Auto-corrected style offenses including string literals, assertion styles, and code formatting
• Added respond_to_missing? method to Bayes class to complement method_missing

Reviewed changes

Copilot reviewed 11 out of 12 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
Gemfile	Added rubocop and rubocop-minitest gems to development group
.rubocop.yml	Created RuboCop configuration with project-specific rules and exclusions
.github/workflows/ruby.yml	Added lint job to CI workflow running RuboCop on Ruby 3.3
lib/classifier/bayes.rb	Added respond_to_missing? method and optimized classify method
lib/classifier/lsi.rb	Updated block parameter syntax and fixed operator precedence in array slicing
lib/classifier/extensions/word_hash.rb	Fixed escaped character in string literal
lib/classifier/extensions/vector.rb	Updated block parameter syntax and fixed operator precedence
test/test_helper.rb	Changed $: to $LOAD_PATH and updated string concatenation
test/lsi/lsi_test.rb	Replaced assert/refute with predicate assertions and assert_operator
test/extensions/word_hash_test.rb	Changed double quotes to single quotes and reordered assert arguments
test/bayes/bayesian_test.rb	Updated assertion styles and added blank lines for readability

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