PS6136: detect retained maximum-context output workspace

[jxsl13]

Summary

Related #887.

Register opt-in advisory PS6136 for maximum-context retained output workspace. Prove selected GPT/Llama constructor ownership, model/head width, complete output observations, one-row common execution and actualRows-times-width bulk execution. Report retained/common/idle bytes and amplification; no automatic lifetime-changing rewrite.

Replay complete authentic GoAI PR1207 sources: before a10a6bff8f7cb0adf695742b6ec677b750b03c28, after 40bf79ae7d93caa9384719c779d38b6ae4aaa8a1. Both original selected constructors report once; both changed constructors remain quiet. The compiler fixture includes all 28 shared and two GPT constructor functions and the profiling API; native/model type scaffolds are explicitly distinguished from authentic source.

Boundaries

Inventory profiling, pending work, constructor/field exposures and fallback paths. Distinguish capacity-wide physical ToHost transfer from first-Vocab logical consumption. Unselected architectures remain silent. Native ownership/completion/external semantics and workload policy require precise reviewed contracts. Full logical consumption or hard-real-time growth prohibition suppresses advice. Measurements are attributed owner results, not new native measurements or universal speed predictions.

Independent local review covered typed receiver identity, successful allocation/error/release paths, invocation-specific aliases and recorder origins, effectful host-copy destinations, and actual bulk extent evidence. The retained adversarial controls exercise each repaired gap. Unknown effects and unclassified observations fail closed.

A final review found and repaired a real initialization-order false positive: correct eventual owner fields do not establish the earlier allocation geometry. Every selected maximum-row/width load must follow its unique initializer, including exact helper/callback invocation boundaries; a helper write must precede all executable returns. Four authentic-source late/conditional initializer mutations first reproduced registered findings and now reject at the intended gate. Rewritten compiler fixtures are fully reprinted/reparsed with source positions and comments so negative tests cannot pass vacuously because of injected positionless AST nodes.

Validation

• Authentic before/after compiler replay, conventional registered analyzer fixture and adversarial dispatch/alias/error/release/host-copy/bulk tests passed.
• Focused race-count3, matching Go1.26 staticcheck, vet and scoped selfscan passed. Ordinary tests run in parallel; all existing tests are retained.
• The previous published head passed all normal installed commit/push gates. The final reviewed initialization-order descendant is 422b759ce0869ae786cea1ed73e6024a28a8299d, preserving published 0f2ff90 and authored 0ca8ad2 ancestry without history rewriting.
• On that corrective descendant, all normal commit gates passed: formatting, vet/build, full two-worker ordinary tests (checks 126.317s / 200.761s; runner 24.916s / 29.667s) and all-level selfscan. All focused PS6136 controls and matching-toolchain scoped checks also passed. No hooks were bypassed.
• The final normal push passed all installed gates: full two-worker race tests (checks 506.123s / 727.405s; runner 100.357s / 106.641s), unchanged full staticcheck, generated documentation (430 pages), plugin build, every benchmark smoke test and final all-level selfscan. The remote head independently matches 422b759ce0869ae786cea1ed73e6024a28a8299d and the worktree is clean.
• GitHub CI on the exact final head passed all 14 jobs. The fresh pre-merge review check found no comments, reviews or review threads; the PR was clean and mergeable. Default-branch commit 161891e8d4f8eff61c8b36885f26658a39e6aa18 was independently verified green on all 14 jobs before merging.

Merged normally at 2026-09-12 19:46:08 UTC as 8a64e6a25a6ca0e0280277bb8e1ab34759e1b5e5, with exact-head matching and no bypass. Issue #887 remains open until the resulting default-branch CI is green.