Add Ruby and BEAM Rust detectors

[andrew]

Adds detection for rb-sys, Magnus, and Rustler using Ruby, Mix, and Cargo dependency signals.

Includes Ruby and Elixir fixtures, keeps the existing mkmf result for rb-sys projects, and guards against plain extconf.rb and Mix projects triggering the new definitions.

[Copilot]

Pull request overview

Adds knowledge-base tool definitions and fixtures/tests to detect Rust integrations used from Ruby and BEAM projects (rb-sys, Magnus, Rustler) based on Ruby/Mix/Cargo dependency signals while avoiding false positives from plain extconf.rb and plain Mix projects.

Changes:

• Adds new knowledge-base tool definitions: rb-sys and Magnus (Ruby), and Rustler (Elixir).
• Introduces Ruby and Elixir fixture projects to exercise the new detectors.
• Extends detect/detect_test.go with high-confidence detection tests and “near-miss” guard tests.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
testdata/rustler-project/native/rustler_project/src/lib.rs	Adds Rustler fixture Rust source file.
testdata/rustler-project/native/rustler_project/Cargo.toml	Adds Rustler fixture Cargo manifest with rustler dependency.
testdata/rustler-project/mix.exs	Adds Rustler fixture Mix project referencing :rustler.
testdata/ruby-rust-project/src/lib.rs	Adds Ruby/Rust fixture Rust source file.
testdata/ruby-rust-project/Gemfile	Adds Ruby/Rust fixture Gemfile with rb_sys gem.
testdata/ruby-rust-project/ext/ruby_rust_project/extconf.rb	Adds Ruby/Rust fixture extconf.rb using rb_sys/mkmf.
testdata/ruby-rust-project/Cargo.toml	Adds Ruby/Rust fixture Cargo manifest with magnus and rb-sys crates.
knowledge/ruby/rb-sys.toml	Adds rb-sys tool definition and detection/config metadata.
knowledge/ruby/magnus.toml	Adds Magnus tool definition and Cargo-based detection metadata.
knowledge/elixir/rustler.toml	Adds Rustler tool definition and Mix/Cargo-based detection metadata.
detect/detect_test.go	Adds tests covering new detectors, confidence levels, and false-positive guards.

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