* Compose class references across unions and collections
- Compare class, function and native references held in differently represented unions with `===`, `!==` and `Object.is` while preserving subclass identity, and refuse comparisons that a structural union arm leaves undecidable
- Keep subclass values intact through base-typed array and Set insertion spreads, `concat`, and inferred class-predicate `filter`/`find`/`findLast`, and allow checked class refinement of captured optional values with several class arms
- Split the sanitized compiler self-rebuild CI job at the IR boundary, after giving sort helpers distinct IR nodes so serialized and in-memory IR emit the same LLVM
* Keep compact comparisons for plain union arms
- Compare a plain operand with a union that already holds its type through the existing inline union comparison, preserving established parameter representations
- Update the coverage expectation for the accepted class refinement
- Enforce oxlint and oxfmt for owned JavaScript and TypeScript with independent CI checks.
- Preserve compiler import boundaries and protected fixtures while cleaning up lint findings.
- Standardize source formatting and validate import, fixture, and embedded-source protections.
- Run command and self-rebuild checks independently in both validation lanes.
- Preserve complete local coverage and native package installation checks.
- Reject invalid phase selection and verify the CI matrix retains every contract.