Add DSL compiler for RuboCop def_node_matcher/def_node_search

[Vein05]

Summary

Adds a new RubocopNodePattern DSL compiler that generates RBI files for RuboCop cops using def_node_matcher and def_node_search macros.

Detection Strategy

• Uses the param0 heuristic to identify macro-generated methods (no false positives across 594+ cops)
• [:opt, :param0] → def_node_matcher, [:req, :param0] → def_node_search
• Reads source_location to extract the pattern string and count captures

Return Type Logic

• def_node_matcher: 0 captures → T::Boolean, 1+ captures → T.untyped
• def_node_search: predicate (?) → T::Boolean, otherwise → T::Enumerator[::RuboCop::AST::Node]
• Handles extra pattern arguments (%1, %2) as additional T.untyped parameters

Status

🚧 Work in progress — initial skeleton with core functionality. Still TODO:

• Edge case handling (multi-line patterns, inline string patterns)
• Error handling for unreadable source locations
• More comprehensive test coverage
• Performance testing against large cop codebases

Resolves #2321

Test plan

• All 8 initial specs passing
• Test against real-world rubocop extensions (rubocop-rails, rubocop-rspec)
• Verify generated RBIs match actual method signatures
• Run full test suite to check for regressions