mytheclipse/.hermes/plans/mytheclipse-round6-spec.md

Implementation Spec: Round 6

New Features

1. HealthCheckedPool (mytheclipse-core, observability+traffic)

File: crates/mytheclipse/src/pool_health.rs

• HealthCheckedPool<T> — wraps SemaphorePool<T>, integrates HealthRegistry
• check_connection(&self) -> HealthStatus — validates pooled resource
• auto-registers health check at construction
• gated feature observability+traffic

2. HkdfKeyDeriver (mytheclipse-crypto, derivation feature)

File: crates/mytheclipse-crypto/src/hkdf.rs

• HkdfKeyDeriver — HKDF-SHA256 (RFC 5869) from master secret
• derive_key(&self, purpose: &str, output_len) -> Vec<u8> — context-specific sub-key
• domain separation via purpose as info
• gated feature "derivation"

3. BackpressureEnqueue (mytheclipse-queue, in-memory)

File: crates/mytheclipse-queue/src/backpressure.rs

• BackpressureEnforcer — tracks in-flight count, enforces max
• enqueue_or_nack(queue, topic, payload, max_inflight) -> Result<(), BackpressureError>
• non-blocking: returns BackpressureError when at capacity

Verification

• build + test + clippy + commit + push