Module tier 

Memory tier management per ADR-136.

Implements the four-tier coherence-driven memory model: Hot (tier 0), Warm (tier 1), Dormant (tier 2), Cold (tier 3).

Tier placement is driven by the residency rule: cut_value + recency_score > eviction_threshold

When the coherence engine is absent (DC-1), cut_value defaults to 0 and only recency_score drives tier placement against a static threshold.

Structs

RegionTierState

Per-region metadata tracked by the tier manager.

TierManager

Manages tier placement for a fixed set of memory regions.

TierThresholds

Static fallback thresholds for tier transitions when the coherence engine is absent (DC-1). All values are in basis points (0..=10_000).

Enums

Tier

The four memory tiers defined in ADR-136.