tokmd-analysis-maintainability

This microcrate owns maintainability-index scoring rules and Halstead-based maintainability updates for tokmd analysis receipts.

Purpose

• Keep SEI maintainability math in one place.
• Keep letter-grade thresholds stable (A / B / C).
• Keep Halstead-to-maintainability integration behavior deterministic.

API

• compute_maintainability_index - compute simplified or full SEI MI.
• attach_halstead_metrics - attach Halstead metrics and refresh MI when valid.