Slice 250.2b Phase 3: BiometricExecutionMatrix + Zero-Trust OOM Circuit Breaker

[drussell23]

Summary

Phase 3 (stacked on #69510). The ECAPA execution matrix + a fail-secure OOM circuit breaker for unified-memory volatility. tests/ml/ only; fully decoupled by structural injection (no unified_supervisor/backend imports).

• BiometricExecutionMatrix: consumes uniform tensors (Phase 2) → embedder (ecapa_facade via lazy structural injection / stand-in) → cosine eval vs stored baseline voiceprint.
• Zero-Trust OOM breaker (LocalOOMCircuitBreaker, structurally AdvancedCircuitBreaker-shaped + injectable): fail-secure — breaker-open / MemoryError / generic error always return VERDICT_REJECTED (never ACCEPTED on error).
• Async RESOURCE_PRESSURE swarm telemetry: on OOM, fire-and-forget ("resource_pressure", {...}) to injected EventSink + SwarmTrigger (loop-task or daemon-thread fallback) — never blocks the secure-lock verdict.

Test Plan

• 57 passed, 3 skipped (real-ECAPA seam)
• Happy path B-accept / C-reject on preprocessed fixtures
• Fail-secure: breaker-open (embedder not called) / OOM / generic error → REJECTED
• OOM proof: sync REJECT + record_failure + resource_pressure event fired + swarm triggered
• Non-blocking: verdict ~1.7ms vs slow sink completing ~302ms later (ordering asserted)
• Breaker trips after N=3 OOMs → 4th short-circuits without invoking the model

🤖 Generated with Claude Code

---

Summary by cubic

Adds a fail-secure ECAPA biometric execution matrix with a zero-trust OOM circuit breaker and non-blocking telemetry, implemented in tests/ml/ via structural injection. Prevents ACCEPT on errors and shields the pipeline from unified-memory OOM storms.

• New Features
  • BiometricExecutionMatrix: embeds a uniform tensor, compares cosine similarity to a baseline, and applies an accept threshold; returns REJECTED on any error.
  • Zero-trust OOM breaker: LocalOOMCircuitBreaker (shape-compatible with AdvancedCircuitBreaker) trips after N OOMs; while open, short-circuits to REJECT without calling the embedder.
  • Async telemetry: on OOM, fire-and-forget resource_pressure events to injected EventSink and SwarmTrigger; never blocks the verdict and works without a running loop (daemon thread fallback).
  • Structural injection: no backend or supervisor imports; optional lazy probe of ecapa_facade; pure NumPy implementation with focused unit tests covering accept/reject paths, breaker-open short-circuiting, OOM handling, and telemetry behavior.

^{Written for commit 3d50f42. Summary will update on new commits.}

[github-actions]

📊 PR Size Analysis

Size: L
Files Changed: 3
Lines Added: +889
Lines Deleted: -0
Total Changes: 889

💡 This PR is large. Ensure it focuses on a single feature or fix.

Review Checklist

• All tests passing
• Code follows project style guidelines
• Documentation updated if needed
• No sensitive data exposed
• Breaking changes documented

[drussell23]

HELD (not merging this session) per operator review: production-shaped component (BiometricExecutionMatrix + OOM breaker) parked in the test tree with no production consumer yet; headline proofs run against stand-in embedders. Hold until the real ECAPA/biometric pipeline is scoped so this is built/validated against reality rather than banked as orphaned scaffolding. Green + isolated; safe to land later. Bases on the P2 branch (now merged to main via #69510).