README: RocksDB and systemd verified on ARM; CLAUDE.md: always test in a venv

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

CLAUDE.md

@@ -8,6 +8,11 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ## Commands
 
+Always run tests, lint and installs in a Python virtual environment (`python3 -m venv venv && . venv/bin/activate`;
+`/venv/` is in `.gitignore`), never with the system pip, also inside Docker containers used to run tests. RocksDB needs
+RocksDB >= 8.0 for `rocksdb-ng`: Debian 12 ships 7.8.3, so on it test RocksDB in a `python:3.14-trixie` container
+(RocksDB 9.10, set `ALLOW_ROOT=1` there because the server refuses to run as root).
+
 ```bash
 pip install -e ".[leveldb,rocksdb]"      # at least one DB engine extra is required
 pip install pytest pytest-asyncio pytest-cov pycodestyle

README.md

@@ -61,12 +61,16 @@ Verified on aarch64 (Raspberry Pi, Debian 12, Docker 29):
 
 - the integration-test node image builds (official `aarch64-linux-gnu` release, signature checked);
 - `tests/integration` with LevelDB: 21 passed; unit tests (without `test_storage.py`): 181 passed; `pycodestyle` clean;
-- the server image builds, `contrib/docker-smoke-test.sh` passes and `rocksdb` imports inside it.
+- the server image builds, `contrib/docker-smoke-test.sh` passes and `rocksdb` imports inside it;
+- `tests/integration` with RocksDB 9.10 (`python:3.14-trixie` container): 21 passed;
+- the systemd unit in `contrib/systemd` starts, syncs a regtest chain, answers on the Electrum protocol and
+  `electrumx_rpc`, and stops cleanly through its `ExecStop`.
 
 Still to do or verify:
 
-- **RocksDB on ARM**: `tests/server/test_storage.py` and `tests/integration` with `PLM_TEST_DB_ENGINE=rocksdb`
-  were not run (they need `librocksdb-dev` and `pip install ".[rocksdb]"`; `rocksdb-ng` is compiled from source).
+- **RocksDB version**: `rocksdb-ng` needs RocksDB >= 8.0 and compiles from source; Debian 12 (7.8.3) is too old,
+  use Debian 13 or the Docker image. In `tests/server/test_storage.py` the 7 RocksDB tests error at teardown with
+  9.10 (the fixture does `os.chdir` before `db.close()` on a relative path), the same on ARM and amd64.
 - **Server image build without cache**: confirm that `rocksdb-ng` compiles on arm64 from scratch
   (`docker build --no-cache -t plm-electrumx .`).
 - **A full sync** of the server image against a real Palladium node on ARM (speed, memory, `CACHE_MB`).