Native-performance regression gate

fak native-performance --gate request.json converts the hill climb into an envelope-scoped regression gate. The request contains the last accepted real receipt, a candidate receipt, and the policy for that exact model, artifact, hardware, controls, engine, and forward path. A policy is never portable across envelopes.

Verdict

The command emits fak-native-performance-gate-verdict/v1 and exits 0 for pass or investigate, 3 for regression, and 1 for invalid/incomparable evidence. It checks all of these together:

• repeated-run coefficient of variation against the envelope noise band;
• end-to-end decode throughput against both the accepted receipt and absolute floor;
• the quality metric captured by the same run;
• fak-native engine and the pinned native forward path;
• zero fallbacks and the envelope peak-memory ceiling;
• derived module@rev movement between accepted and candidate receipts.

A noisy run or a loss inside the investigate band asks for another sanctioned capture. A material loss or any quality/identity/fallback/memory/floor failure is a regression. Non-pass verdicts include a sorted suspect module set and a fak-native-performance-bisect-packet/v1 with the known-good/bad revisions, lane-acquisition command, rerun command, and witnessed stop condition. The packet never switches engines or normalizes across devices.

Cadence and evidence

Local presubmit runs the deterministic package/CLI tests only; hardware is not a universal PR blocker. The scheduled/manual native-performance-regression workflow dispatches the public request artifact to the private sanctioned runner bridge documented in docs/private-comms-channel.md. The private side must run the pinned Metal or CUDA campaign, retain raw logs privately, and return only the scrubbed request and verdict. A scheduled result is accepted only when the receipt names fak-native, the exact forward path, quality, zero fallbacks, memory, repetitions, and module revisions.

Override requires a maintainer-owned issue containing: the scrubbed candidate receipt, repeated rerun showing the classification, quality review, reason the floor changes, new envelope-specific policy, and rollback revision. Rollback is the last accepted revision from the verdict. Never weaken a different envelope, waive the gate with self-authored output, or publish hosts, credentials, private paths, or raw profiler logs.

Focused witness:

$env:FAK_FAST='0'; .\test.ps1 -count=1 ./internal/nativeperf
$env:FAK_FAST='0'; .\test.ps1 -count=1 -run '^TestNativePerformance' ./cmd/fak