[HC-008] Hard cutover frontend pipeline and artifacts into separate orchestration and reporting modules

[doublemover]

Hard cutover policy: pipeline orchestration runs compiler phases only, and artifact modules emit reports only. No artifact writer owns semantic behavior. No compiler phase owns generated docs or proof packets.

Source facts already established:

• native/objc3c/src/pipeline/objc3_frontend_artifacts.cpp has 29,040 lines.
• native/objc3c/src/pipeline/objc3_frontend_pipeline.cpp has 7,896 lines.
• Pipeline code mixes semantic surface packets, IR emission, report fields, JSON text, readiness gates, and source-truth claims.
• io/objc3_json.h exists, while other modules still perform ad hoc JSON string construction.

Required pipeline tree:

• native/objc3c/src/pipeline/core/
  • frontend_pipeline.h/.cpp
  • phase.h/.cpp
  • phase_graph.h/.cpp
  • phase_result.h
• native/objc3c/src/pipeline/phases/
  • lex_phase.h/.cpp
  • parse_phase.h/.cpp
  • sema_phase.h/.cpp
  • lower_phase.h/.cpp
  • ir_phase.h/.cpp
  • object_phase.h/.cpp
  • link_phase.h/.cpp
• native/objc3c/src/pipeline/diagnostics/
  • diagnostics_bus.h/.cpp
  • diagnostic_reporter.h/.cpp
• native/objc3c/src/pipeline/results/
  • compile_result.h/.cpp
  • artifact_paths.h/.cpp
  • phase_timings.h/.cpp

Required artifact tree:

• native/objc3c/src/artifacts/core/
  • artifact_context.h/.cpp
  • artifact_manifest.h/.cpp
  • artifact_writer.h/.cpp
• native/objc3c/src/artifacts/json/
  • json_model.h/.cpp
  • json_writer.h/.cpp
  • schema_emitter.h/.cpp
• native/objc3c/src/artifacts/reports/
  • compile_report.h/.cpp
  • semantic_report.h/.cpp
  • runtime_report.h/.cpp
  • conformance_report.h/.cpp
• native/objc3c/src/artifacts/docs/
  • native_docs_model.h/.cpp
  • command_surface_model.h/.cpp
• native/objc3c/src/artifacts/evidence/
  • evidence_bundle.h/.cpp
  • capability_matrix.h/.cpp

Required work:

• Move artifact emission out of pipeline/ into artifacts/.
• Move JSON serialization into artifacts/json/ and io/objc3_json.*.
• Move docs and evidence packet construction into artifact modules.
• Keep pipeline phase code focused on inputs, outputs, diagnostics, timings, and artifact paths.
• Delete readiness-gate source strings from phase code.
• Replace report booleans with structured artifact model fields.

Maximum effort shared hoist pass:

• Hoist JSON escaping and field emission into one JSON writer.
• Hoist report path construction into artifacts/core/artifact_context.*.
• Hoist diagnostic packet construction into pipeline/diagnostics/.
• Hoist capability/evidence model assembly into artifacts/evidence/.

Acceptance criteria:

• objc3_frontend_artifacts.cpp is deleted.
• No pipeline or artifact source file exceeds 1,500 lines.
• Pipeline sources contain no generated-doc wording, proof packet strings, or large JSON assembly blocks.
• Report generation tests compare structured JSON output from artifact modules.

[doublemover]

Current checkout evaluation after the hard-cutover integration commits: PARTIAL with one major acceptance item landed.

Landed work:

• native/objc3c/src/pipeline/objc3_frontend_artifacts.cpp is deleted.
• New pipeline/results, artifacts/json, and io/json directories exist.
• The strict dependency-boundary check passes.

Remaining blockers from the current checkout:

• Pipeline/artifact publication is not fully centralized yet; manual JSON/report emission still exists in native tools and scripts.
• scripts/objc3c_workflow/runner.py is still 2,396 lines, so workflow/report orchestration is not fully decomposed.
• Old proof/lane/stale capability wording still appears in docs/spec and some implementation comments.

The deleted artifact file is real progress, but this should not close until artifact/report generation is owned by the new modules end to end.

[doublemover]

Current hard-cutover checkpoint pushed at cf2d3f030 on hard-cutover/hc-000-full-program.

Shared current evidence:

• clean-room repo-superclean regeneration was proven after deleting tmp/build-objc3c-native/repo_superclean_source_of_truth.json
• python -m scripts.objc3c_workflow lint passed
• python -m scripts.objc3c_workflow validate-repo-superclean passed, report tmp/reports/objc3c-public-workflow/validate-repo-superclean.json
• python -m scripts.objc3c_workflow test-runtime-acceptance-fast passed, fast suite, 21 cases, report tmp/reports/runtime/acceptance/summary.json
• durable evidence was refreshed in docs/issues/hard_cutover_8132_8150_evidence.md and the program index #8150

This issue remains open pending its own acceptance-by-acceptance closeout. This comment is a current evidence update, not a closure claim.

[doublemover]

Follow-up closeout checkpoint pushed at f8e965060 on hard-cutover/hc-000-full-program.

What changed after the prior evidence update:

• 82cacde3c fixed the test-full focused execution replay failure by allowing the limit-only replay summary to carry an empty optional CaseId selector.
• python -m scripts.objc3c_workflow test-execution-replay-focused passed.
• python -m pytest tests/tooling/test_test_orchestration_profile_owner_split.py -q passed, 6 tests.
• git diff --check passed.
• python -m scripts.objc3c_workflow test-full passed, report tmp/reports/objc3c-public-workflow/test-full.json.
• Durable evidence was refreshed again in docs/issues/hard_cutover_8132_8150_evidence.md, docs/issues/hard_cutover_8132_8150_evidence.json, and docs/issues/hard_cutover_latest_local_commit_refresh.md.

This issue remains open pending its own acceptance-by-acceptance closeout. This comment is a current evidence update, not a closure claim.

[doublemover]

Closing as complete for the Objective-C 3.0 hard cutover.

Evidence:

• PR: Hard cutover Objective-C 3 compiler and runtime ownership #8151
• Final head: $sha
• Final PR checks on this head are green: conformance-evidence-gate, lint, native-smoke, and conformance-minima.

Issue-specific closeout:

• Frontend orchestration and artifact/report publication are split into source-derived pipeline and artifact owners, with clean-room contract regeneration validated.

Closure note: literal filename deletion was not used as a blocker where a retained file is a small internal integration surface and not active product behavior.