Review implementation quality for this feature group.

For every feature listed, verify the implementation:
- Has complete and accurate JSDoc on all public functions, types, and classes.
- Is clean, production-ready code.
- Prefers inlining over abstraction — only abstract if the pattern is used more than once.
- Has ZERO magic strings or magic numbers — all such values must be named constants.
- Has no dead code, unused imports, or commented-out code.

If you see any way to improve the code, improve it.
Score 0–100 based on code quality AFTER your fixes.
