docs: withdraw the ZeroClaw integration claims

CLAUDE.md said ZeroClaw "imports this as a Cargo feature (clawhdf5
feature flag)" and uses clawhdf5 as its memory backend; the agent crate
called itself the "ZeroClaw agent memory HDF5 backend"; the migrator
claimed to read "the ZeroClaw layout". Checked on 2026-09-25 against
ZeroClaw v0.8.5 (its latest release), the osobh/zeroclaw fork (on
v0.8.5) and both histories back to February 2026:

- no `clawhdf5` feature, dependency or memory backend has ever existed
  in ZeroClaw; its backends are sqlite, lucid, postgres, qdrant,
  markdown and none, behind its own `Memory` trait;
- ZeroClaw's SQLite schema is a single `memories` table (id, key,
  content, category, embedding, created_at, updated_at); the
  migrator's memory_chunks/sessions/entities/relations layout never
  existed in ZeroClaw, so it cannot read a ZeroClaw database.

Decision: withdraw the claims (as with OpenClaw); clawhdf5 is a
standalone library with no framework integration. The migrator's
default layout is documented as its own. ZEROCLAW_VERSION keeps its name
and value (it is the persisted `edgehdf5_version` writer tag) with a
doc comment saying it is unrelated to ZeroClaw.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

CLAUDE.md

@@ -1,7 +1,7 @@
 # clawhdf5
 
 ## Purpose
-Pure-Rust HDF5 format implementation with HNSW vector search, WAL-backed persistence, agent memory storage, and GPU-accelerated I/O. Used by ZeroClaw as its persistent memory and knowledge graph backend.
+Pure-Rust HDF5 format implementation with HNSW vector search, WAL-backed persistence, agent memory storage, and GPU-accelerated I/O. A standalone library: no agent framework currently integrates it (OpenClaw and ZeroClaw claims were withdrawn on 2026-09-25 — neither was ever true).
 
 ## Architecture
 
@@ -109,7 +109,15 @@ Cargo workspace with 16 crates under `crates/` (plus `libaec-sys`, an internal F
 - **OpenClaw is not supported** (decided 2026-09-25): clawhdf5 is not an
   OpenClaw memory plugin and never was — the old `memory.backend = "clawhdf5"`
   config was never valid. Don't reintroduce OpenClaw claims; `docs/openclaw.md`
-  records what a real plugin would need. ZeroClaw is the integration target. Measure changes with
+  records what a real plugin would need.
+- **ZeroClaw does not use clawhdf5** (checked 2026-09-25 against upstream
+  v0.8.5 and the `osobh/zeroclaw` fork, and their full history): no
+  `clawhdf5` feature or backend exists; ZeroClaw's memory backends are
+  sqlite/lucid/postgres/qdrant/markdown/none behind its own `Memory` trait.
+  `clawhdf5-migrate`'s default SQLite layout (`memory_chunks`, `sessions`,
+  `entities`, `relations`) is not ZeroClaw's schema either (ZeroClaw's is a
+  `memories` table). Don't reintroduce integration claims without an
+  integration and a test against the real consumer. Measure changes with
   `search_harness --options-study`.
 - `MemoryConfig::compression` is off by default; when on, embeddings are
   deflate-compressed, or Zstd with the agent's `zstd` feature (links libzstd).
@@ -188,4 +196,5 @@ python -c "import clawhdf5; print(clawhdf5.__version__)"
 ```
 
 ## Integration
-ZeroClaw imports this as a Cargo feature (`clawhdf5` feature flag) to persist agent memory with HNSW vector search for context retrieval.
+None today. OpenClaw and ZeroClaw were both described as consumers; neither
+integrates clawhdf5 (see Key Features and `docs/openclaw.md`).