Migrate implicit self, constant, parameter, and definition tests to Ruby

[dak2]

Motivation

The Rust analyzer tests for implicit self calls, constant reads, parameters, and definitions were full-pipeline integration tests (parse → install → propagate → resolve) that duplicated Ruby integration tests. This migration removes redundant Rust tests and moves unique scenarios to Ruby, keeping only true unit tests that verify internal state not observable through the CLI.

Changes

• definitions.rs: 20 → 12 tests (removed 8 redundant tests covering method registration, class methods, and namespace resolution)
• dispatch.rs: Removed implicit self call (5), constant read (7), and keyword arg (5) redundant tests; cleaned up unused get_type_show helper
• parameters.rs: 11 → 3 tests (removed 8 redundant tests, kept only internal env-level unit tests)
• implicit_self_call_test.rb: Added 2 tests (implicit self in module, implicit self from block)
• constant_read_test.rb: Added 1 test (deeply nested Api::V1::User resolution)
• parameter_test.rb: Added 1 test (keyword arg via .new → initialize)

Checked

• cd core && cargo test --lib — all pass
• bundle exec rake test — all pass

🤖 Generated with Claude Code