Implementation reference

This area preserves useful implementation and historical governor documentation while the public engine API is prepared for 8.0.0. Documentation visibility does not make an internal function a supported package API.

Start with the engine API transition and per-method dispositions. Entries distinguish current 7.x engine availability, proposed 8.x removal, and separately decided standalone exports. No new public imports or conformance test-engine routes are introduced by these pages.

Concise signatures, effects and invariants belong beside source implementations. These pages retain explanations, migration context and links; supported standalone functions must remain discoverable as supported API when their dispositions are decided.