Segment 9
This sub-session successfully finalized both remaining milestones for the FGW enterprise-grade features. For Milestone 03 (Persistent Retrieval Caches), the L2 SSD Cache was created with SLRU eviction, adaptive admission policy, write buffering, and on-disk persistence; an Access Tracker was built with decaying popularity counters and sequential/group access pattern detection; and a DAG-aware Prefetch Engine was implemented with sequential pattern detection and priority queue scheduling. These components were integrated into the retrieval provider and cache manager, replacing the basic LRU cache with a multi-tier L1 ARC and L2 SSD hierarchy, with all new configuration options added. For Milestone 04 (Data Lifecycle Management), the passive GC system was fully built, including CQL and SQL schema migrations for reverse indices (GroupToMultihash), GC state tracking (GcCandidateGroups, GcCandidateClaims), and a reference counter (MultihashRefCount) for tracking live block references. The GC algorithm marks dead objects for non-renewal, and the claim extender was modified to skip GC-candidate groups. Configuration options for GC thresholds, repair worker intervals, and backup settings were added, and the existing repair worker logic was enabled. All new code compiles and tests pass successfully.