Integrate OPY lowering and end-to-end compatibility with workshop-rs

[Teakowa]

Parent: #1

Goal

Connect the completed OPY semantic frontend to canonical workshop-rs semantics and finish the Workshop-dependent parts of OverPy compiler compatibility.

Current readiness

The pre-integration gate #7 and integration-boundary issue #35 are complete. The merged support matrix currently reports:

• planned: 0
• frontend-supported: 23
• semantic-supported: 13
• lowering-dependent: 13
• end-to-end-supported: 1 bounded Establish the versioned OPY-to-Workshop integration boundary #35 vertical slice

The active dependency direction is:

OPY source -> opy-frontend -> OPY HIR -> opy-compiler -> workshop-rs WIR -> Workshop text

opy-frontend remains Workshop-independent so check/inspect/source tooling does not require the compiler backend. workshop-rs = "=0.1.1" is the current published integration baseline. wrightkit/workshop-rs#10 strengthens shared conformance/census evidence but does not block this baseline.

Execution issues

• Establish the versioned OPY-to-Workshop integration boundary #35 — Establish the versioned OPY-to-Workshop integration boundary
• Lower the declared OPY semantic surface into canonical Workshop WIR #36 — Lower the declared OPY semantic surface into canonical Workshop WIR
  • Lower OPY program structure into canonical Workshop WIR #40 — Program structure
  • Lower OPY statements and expressions into canonical Workshop WIR #41 — Statements and expressions
  • Close catalog-backed OPY lowering and corpus evidence #42 — Catalog-backed semantics and corpus closure
• Integrate Workshop-dependent settings, locale, directive, and hook behavior #37 — Integrate Workshop-dependent settings, locale, directive, and hook behavior
• Expose OPY compilation and close the end-to-end compatibility gate #38 — Expose OPY compilation and close the end-to-end compatibility gate

Intended order: #40 → #41 → #42 → close #36 → #37 → #38. Work may overlap only where public contracts are established and branches remain independently reviewable.

Scope

• Consume workshop-rs through documented public contracts and an explicit implementation/catalog identity.
• Resolve canonical actions, values, events, enums, settings, and locale behavior through workshop-rs; do not duplicate Workshop data in opy-rs.
• Preserve OPY-specific signatures, aliases, contextual dispatch, preprocessing state, source spans, and source semantic identity in opy-rs.
• Lower the declared OPY semantic program into validated canonical WIR.
• Complete supported settings, locale/emission, backend directive, and post-compile-hook behavior at the correct integration stage.
• Expose compilation as a standalone library/CLI capability only after the pipeline has real end-to-end evidence.
• Advance compatibility states only with corpus/differential evidence based on observable semantics, not emitted-text identity.
• Reassess remaining compiler and reconstruction work after the integration baseline is complete.

Non-goals

• Adding workshop-rs directly to opy-frontend.
• Reintroducing canonical Workshop semantics, catalog/member lists, settings tables, or locale data into opy-rs.
• Coupling workshop-rs back to OPY/provider-specific semantics.
• Matching upstream temporary variables, formatting, optimizer internals, or generated text where observable semantics do not require it.
• Freezing or implementing Workshop -> OPY reconstruction before end-to-end compilation provides evidence.
• Blocking basic integration on completion of the full workshop-rs#10 seasonal conformance workflow.

Acceptance criteria

• Establish the versioned OPY-to-Workshop integration boundary #35-Expose OPY compilation and close the end-to-end compatibility gate #38 are complete with independent implementation/test evidence.
• opy-frontend remains independently usable without a workshop-rs dependency.
• OPY semantic identities/signatures link to canonical Workshop identities without duplicating authoritative Workshop data.
• Supported OPY corpus cases lower to structurally valid and catalog-valid WIR and emit through workshop-rs.
• Settings, catalog-backed builtin/member/enum validation, locale/emission behavior, backend-affecting directives where supported, and post-compile hooks have integration tests.
• Post-compile hooks receive the real final emitted Workshop text, never HIR/WIR/JSON or a fabricated payload.
• A documented library/CLI compile surface exists with structured failure behavior suitable for tooling and CI.
• End-to-end compatibility status is evidence-backed; known gaps remain explicit and are not counted as success.
• Cross-repository ownership and dependency direction remain explicit and tested.

Dependencies

• Reach Workshop-independent OPY frontend completeness and expose tooling APIs #7 — completed.
• Establish the versioned OPY-to-Workshop integration boundary #35 — completed.
• wrightkit/workshop-rs#2 — completed.
• workshop-rs 0.1.1 — current published integration baseline; future version changes must be explicit and revalidated.
• wrightkit/workshop-rs#10 — follow-on conformance/census evidence; not a blocker for the baseline.

Planning notes

Do not create another generic backend abstraction or temporary Workshop IR. Use the existing workshop-rs public WIR/catalog/emitter contracts directly through opy-compiler. Further splitting should be evidence-driven rather than speculative.