docs(8.0): consistency-model concept + snapshots guide — Db API replaces branching docs

docs/architecture/data-storage-architecture.md

@@ -4,6 +4,17 @@
 
 This document explains how Brainy stores, indexes, and scales data on disk and in memory.
 
+> **8.0 accuracy note (internal):** this reference describes the pre-8.0
+> layout. In 8.0 the copy-on-write subsystem (`_cow/`, branch-scoped
+> `branches/{branch}/...` paths) was replaced by generational MVCC:
+> canonical entity files live at `entities/nouns/{shard}/{id}/...` with
+> history under `_generations/` and the commit watermark in
+> `_system/manifest.json`. The authoritative 8.0 records are
+> [ADR-001 (generational MVCC)](../ADR-001-generational-mvcc.md) and
+> [index-architecture.md](./index-architecture.md); the COW sections below
+> are retained only as historical context until this document's full
+> rewrite.
+
 ---
 
 ## Table of Contents

docs/architecture/multiprocess-storage-mixin.md

@@ -32,7 +32,7 @@ on `BaseStorage`.
 
 `BaseStorage` already mixes several concerns:
 - entity / verb CRUD primitives
-- COW (copy-on-write) lifecycle
+- generational record hooks (8.0 MVCC)
 - type-statistics tracking
 - count persistence
 - multi-process safety (new)