feat(ruby): add Ruby on Rails command support

[Maimer]

feat(ruby): add Ruby on Rails command support

Summary

Add comprehensive Ruby on Rails support to rtk with 3 new command modules, 1 TOML filter, shared utilities, and automatic discover/rewrite rules.

New Commands

Command	Module	Strategy	Token Savings
rtk rake test	rake_cmd.rs	State machine text parser (Minitest)	85-90%
rtk rspec	rspec_cmd.rs	JSON parsing with text fallback	60%+
rtk rubocop	rubocop_cmd.rs	JSON parsing, group by cop/severity	60%+
rtk bundle install	bundle-install.toml	TOML filter (strip Using lines)	70%

Discover/Rewrite Rules

All common Ruby invocation patterns are automatically rewritten by the Claude Code hook:

rake test              → rtk rake test
bundle exec rake test  → rtk rake test
rails test             → rtk rake test
bin/rails test         → rtk rake test
bundle exec rspec      → rtk rspec
bundle exec rubocop    → rtk rubocop
bundle install         → rtk bundle install
bundle update          → rtk bundle update

ENV_PREFIX auto-strips RAILS_ENV, WITH_COVERAGE, BUNDLE_GEMFILE and re-prepends to the rewritten command (e.g. WITH_COVERAGE=true bundle exec rake test → WITH_COVERAGE=true rtk rake test).

Shared Infrastructure

• ruby_exec(tool) in utils.rs: Auto-detects bundle exec when Gemfile exists in working directory. Handles transitive dependencies correctly (e.g. rake pulled in via rails not listed directly in Gemfile).
• fallback_tail(output, n): Returns last N lines on parse failure (graceful degradation).
• exit_code_from_output(output): Unix signal handling for child process exit codes.
• count_tokens(text): Test utility for token savings verification.

Minitest Parser Details (rake_cmd.rs)

State machine with 4 states: Header → Running → Failures → Summary

• Handles both standard Minitest format (# Running:, N runs) and minitest-reporters format (Started with run options, N tests)
• All pass → one-line summary: "ok rake test: 8 runs, 0 failures"
• Failures → summary line + numbered failure blocks with test name, file:line, assertion message
• Graceful fallback to raw output on parse failure

Testing

• 108 new tests across rake_cmd (11), rspec_cmd (97+), rubocop_cmd tests
• 4 inline TOML tests for bundle-install filter
• Token savings verified ≥60% for all filters
• All 989 tests passing (cargo test)

Documentation

• README.md: Added Ruby commands to savings table, usage examples, and hook rewrite table
• CHANGELOG.md: Added Unreleased section with all Ruby features
• ARCHITECTURE.md: Added Ruby module table entry and full Ruby Module Architecture section
• CLAUDE.md: Updated module responsibilities and fork-specific features

Commits

1. feat(ruby): add RSpec and RuboCop filters with shared Ruby utilities — rspec_cmd.rs, rubocop_cmd.rs, utils.rs additions, test-ruby.sh
2. feat(ruby): add minitest filter for rake/rails test — rake_cmd.rs with state machine parser
3. feat(ruby): register rake/rspec/rubocop commands and rewrite rules — main.rs routing, discover/rules.rs patterns
4. feat(ruby): add TOML filter for bundle install/update — bundle-install.toml, filter count update
5. docs(ruby): update documentation — README, CHANGELOG, ARCHITECTURE, CLAUDE.md

Test Plan

• cargo fmt --all --check passes (our files)
• cargo clippy --all-targets passes (no new warnings)
• cargo test — 989 tests pass, 3 ignored
• Token savings ≥60% verified for all new filters
• Manual testing with real Ruby/Rails projects (rake test, rspec, rubocop, bundle install)
• Minitest parser handles both standard and minitest-reporters formats
• Discover/rewrite rules correctly handle all invocation patterns including bin/rails and env var prefixes
• DCO sign-off on all commits

🤖 Generated with Claude Code