Module audit 

M48 audit trait + types — re-exported from ppoppo-sdk-core.

Phase A (RFC RFC_2026-05-08_app-credential-collapse.md) lifted the whole audit module to ppoppo-sdk-core::audit so multiple SDK crates (pas-external, future pas-plims, pcs-external 0.3.0) and 1st-party services consume one shared trait + impl set.

Consumer-facing imports stay at pas_external::audit::* and pas_external::* (top-level re-export) — relocation is invisible.

Audit utilities (MemoryAuditSink, RateLimitedAuditSink, MemoryRateLimiter, NoopAuditSink) are co-located with the trait in sdk-core because the audit module is one cohesive unit (utility impls are not pas-external-domain-specific).

Structs

AuditEvent

Single typed event emitted on every BearerVerifier::verify rejection.

MemoryRateLimiter

In-memory token-bucket limiter — Phase 9 default substrate.

NoopAuditSink

Default sink — explicitly does nothing.

RateLimitKey

Opaque per-source bucket key for a RateLimiter.

RateLimitedAuditSink

Wraps any AuditSink with any RateLimiter.

Enums

IdTokenFailureKind

id_token-specific failure classification (Phase 10.11.B).

VerifyErrorKind

Failure classification — mirrors the VerifyError and IdVerifyError surfaces but lives at the audit layer.

Traits

AuditSink

Audit emission port for verify-failure events (M48).

RateLimiter

Per-source rate-limiting port (M49).

Functions

compose_id_token_source_id

Phase 10.11.D δ2 — id_token compound source key from azp ‖ aud ‖ kid.

compose_source_id

Compose a Phase 9 (e) compound source key from optional hints.