Lower the declared OPY semantic surface into canonical Workshop WIR

[Teakowa]

Parent: #8
Depends on: #35 (completed), #52 (completed)

Goal

Complete the declared OPY semantic lowering surface into valid canonical workshop-rs WIR and close this stage with representative corpus evidence.

Current execution state

• Lower OPY program structure into canonical Workshop WIR #40 — program structure
• [integration] Rebaseline opy-compiler on current workshop-rs release #52 — rebaseline opy-compiler on the published Workshop contract
• Lower OPY statements and expressions into canonical Workshop WIR #41 — statements and expressions
  • Lower OPY assignment and expression primitives into canonical Workshop WIR #46 — assignment and expression primitives
  • Lower OPY control flow into canonical Workshop WIR with oracle evidence #47 — control flow with oracle evidence, merged via PR feat(opy-compiler): lower control flow into canonical WIR #61 against workshop-rs 0.1.11
• Close catalog-backed OPY lowering and corpus evidence #42 — catalog-backed builtin/member/enum lowering and corpus closure (active edge)

Current execution order:

#42 → close #36

Explicit follow-ups #58/#59/#60/#65 and wrightkit/workshop-rs#95 remain outside this gate unless representative end-to-end evidence proves one blocks the declared baseline.

Scope

• Map the declared OPY semantic program into canonical workshop-rs WIR without another Workshop IR.
• Preserve source provenance and structured failure behavior across the integration boundary.
• Resolve canonical Workshop identities through workshop-rs; never copy authoritative catalog/member/enum data into opy-rs.
• Implement OPY-specific special lowering only where observable behavior is backed by pinned oracle/corpus evidence.
• Use wir::Program::validate and canonical catalog validation as correctness gates.
• Close with representative synthetic and real-world corpus evidence, keeping unsupported cases explicit.

Non-goals

• Settings, locale selection, backend directive effects, and #!postCompileHook execution (Integrate Workshop-dependent settings, locale, directive, and hook behavior #37).
• Workshop→OPY reconstruction ([design] Re-evaluate Workshop → OPY reconstruction scope after workshop-rs rebaseline #53 design lane).
• Output-text identity, upstream temporary-variable allocation, or optimizer-internal parity.
• A provider-neutral backend abstraction or temporary Workshop IR.

Acceptance criteria

• Lower OPY program structure into canonical Workshop WIR #40, Lower OPY statements and expressions into canonical Workshop WIR #41, and Close catalog-backed OPY lowering and corpus evidence #42 are complete with independent implementation/test evidence against the revalidated Workshop baseline.
• Every HIR node claimed by the current public support contract either lowers to valid canonical WIR or remains an explicit evidence-backed gap.
• Produced WIR passes structural and canonical-id validation.
• Source provenance remains attached through integration diagnostics and WIR where supported by the public contract.
• Canonical builtin/member/enum existence is decided through workshop-rs, not duplicate local data.
• Representative real-world corpus cases reach deterministic Workshop emission with no unexpected semantic divergence in the supported slice.
• Compatibility status advances only when executable end-to-end evidence exists.