Maintain exhaustive pinned OverPy feature-contract inventory and leaf coverage

[e54-bot]

Goal

Keep opy-rs compatibility claims grounded in an implementation-derived inventory of the pinned OverPy source surface and executable evidence for each materially distinct external contract.

Context

OverPy compatibility includes source forms, contextual dispatch, preprocessing, macros, project composition, settings, translations, directives, compiler/lowering behavior, diagnostics, and tooling. A small set of representative fixtures can remain green while an upstream registry branch or consumer context is unimplemented or untested. The inventory must therefore be derived from the pinned OverPy revision rather than from the existing opy-rs support matrix.

Scope

Maintain the pinned-revision feature-contract inventory and its relationship to opy-rs production implementation, executable conformance/regression evidence, and ownership boundaries. Keep source-language contracts distinct from canonical Workshop facts owned by workshop-rs, and keep implementation status separate from evidence coverage.

Non-goals

This issue does not prescribe a particular inventory file format, implement individual missing OverPy features, redefine canonical Workshop semantics, require internal upstream architecture identity, or replace focused regressions and real-project corpus evidence with a feature count.

Acceptance criteria

• Every user-visible feature family and relevant non-registry parser/compiler branch in the pinned OverPy revision has a provenance-linked contract entry.
• Materially distinct syntax, context, lifecycle, diagnostic, lowering, and project-composition branches are represented separately when their observable behavior differs.
• Each implemented-and-covered claim identifies production implementation evidence and executable evidence that exercises the claimed contract; broader rows identify their coverage limits.
• Missing, partial, intentionally unsupported, external-owner, and unclear states remain explicit and are not inferred from support-matrix presence alone.
• Conformance/support reporting can detect when an upstream registry entry or compiler branch is absent from the inventory or lacks leaf-level evidence.
• The inventory and evidence remain tied to an immutable OverPy revision and preserve the opy-rs/workshop-rs ownership boundary.

Dependencies / ownership

opy-rs owns the OPY source, preprocessing, semantic, diagnostic, tooling, and OPY-specific lowering contracts and their evidence. workshop-rs owns canonical Workshop catalog, WIR, settings, locale, validation, and emission facts. Changes to the pinned OverPy revision require an explicit provenance and compatibility review.