b0a760c0ab
Schema: - Inheritance: multi-level, property merging, override, isSubtype - Computed properties with expressions - getSubtypes for polymorphic queries Codegen: - IR plan → storage operations compilation - Predicate pushdown optimization (filter → point read) - Cost estimation and EXPLAIN output Replication: - Sync replication (wait for all replicas) - Async replication (fire and forget) - Semi-sync (wait for N replicas) - Replica state tracking and lag monitoring Storage: - Memory-mapped I/O for SSTable access - Sequential/random access hints (madvise) - Page-level read operations 29 new tests (136 total, all passing)