docs(engine-plan): 2026-08-06 ticket sync and repsel stack position

[proggeramlug]

Syncs the canonical plan to ticket reality after today's fixes:

• Copying minor loses ObjectHeader::keys_array on large/infrequent cycles — pre-existing, unmasked by #7432; blocks the public baseline #7472 → fixed by fix(json): validate the untagged key pointer in stringify_object_inner (#7472) #7473 (default JSON.stringify path verified byte-equal to node), closed
• perf: array element store pays a cross-crate guard call per element (15% of bench_array_ops) #7396 → closed as fixed-by-perf(codegen): inline the numeric array store guard for element-to-element writes #7421, with the A/B evidence (tier live 125 ms vs forced-cold 1731 ms) in its thread
• app-patterns: object_deep_clone and promise_all_chains fail only under the auto-optimize path; blocks the public baseline #7475 is now the sole public-artifact blocker (auto-optimize archive, pre-existing, isolated)
• instance_private_key_hidden faults under PERRY_GC_SCAVENGE_NURSERY_MB=64 (residual from #7472) #7481 filed so the non-default-cap instance_private_key_hidden fault doesn't vanish inside closed Copying minor loses ObjectHeader::keys_array on large/infrequent cycles — pre-existing, unmasked by #7432; blocks the public baseline #7472 — with the shared lesson that a large-Eden ratchet-probe arm would have caught both
• Repsel stack position recorded: phases 1–4a merged (perf(codegen): representation-selection Phase 3a — canonical string locals (tagged-at-rest Str rep) #6909/perf(codegen): representation-selection Phase 3b — shape-proven object locals (Ptr<Shape>, delete the guard diamond) #6911/perf(codegen+runtime): representation-selection Phase 4a — fast plain-array numeric elements (inline tiers, holes axis, self-healing bindings) #6915 + perf(codegen): inline the numeric array store guard for element-to-element writes #7421/perf(codegen): revive the class-field versioned loop for canonical-i32 counters #7425), 4b in flight, element-shape route decided in repsel: element-shape proofs through arrays — measured 6.2× vs node; route = invariant bit → versioned-loop consumer → element Ptr<Shape> #7480 (invariant bit → versioned-loop consumer → element Ptr<Shape>), all phases gated on the full gap suite per perf(codegen): keep the numeric-array specialization when the array is captured (#6369) #6377

Docs only.

Summary by CodeRabbit

• Documentation
  • Updated the engine sequencing plan with current ticket and benchmark-blocker status.
  • Documented the ordered JSON parser workstream, validation requirements, and parallel execution progress.
  • Added repsel campaign updates, including completed phases, phase 4b progress, and the next prerequisite.
  • Added a changelog entry summarizing the plan synchronization.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 3f759a29-1135-4957-b3ac-985e99b11db9

📥 Commits

Reviewing files that changed from the base of the PR and between 551e2a8 and bc345a3.

📒 Files selected for processing (2)

• changelog.d/7482-plan-ticket-sync.md
• docs/engine-plan.md

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📝 Walkthrough

Walkthrough

The engine plan now records current ticket status, benchmark blockers, residual cap behavior, ordered JSON parser work, and representation-selection progress through phase 4b. A changelog entry documents these updates.

Changes

Engine plan synchronization

Layer / File(s)	Summary
Ticket status updates docs/engine-plan.md, changelog.d/7482-plan-ticket-sync.md	The plan records resolved tickets, the remaining artifact blocker, residual cap behavior, benchmark status, and related findings.
Representation-selection sequencing docs/engine-plan.md	The plan records merged phases through 4a, in-progress phase 4b, and the next array element-shape prerequisite with full-suite baseline gating.

Estimated code review effort: 1 (Trivial) | ~3 minutes

Possibly related PRs

• PerryTS/perry#7293: Updates the engine plan with representation-selection campaign status.
• PerryTS/perry#7479: Updates the engine plan with overlapping JSON workstream sequencing.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch docs/plan-ticket-sync

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