docs: the review classifier's try-out service, its key and its subject

- review-classifier.md: claude runs spawn through hive-claude directly
  with no tools and no session (hive-runtime holds only TurnStop); the
  answer's fields, the 500-character reason cap and what a failure does;
  how the try-out page reaches the classifier; the settled parts of the
  open list (API key path, try-out subject, --tools "" on claude).
  The banner stays.
- services.md: a Review classifier section with the two operator steps.
- secrets.md, credentials.md: the classifier's leaf and the key row.
- network.md: the container's row. CLAUDE.md: the crate.

CLAUDE.md

@@ -187,6 +187,12 @@ hand-maintained per-file tree drifts out of sync with the code.
   defaults look for `VAULT_ADDR`/`VAULT_CLIENT_CERT`/`VAULT_CLIENT_KEY`, which
   no unit in this tree sets, so falling through to them yields a client with
   **no identity** and a TLS handshake failure that names no cause.
+- **`swarm-review-classifier/`** — the review classifier's try-out daemon,
+  in its own container where `deploy.review-classifier.enable` is set. Takes
+  a PR and classifications from `swarm-controller` over the queue, runs one
+  `claude --print` per classification (no tools, no session) and replies
+  with the rows and the overall verdict. Holds no forge credential. Design:
+  [`docs/swarm/review-classifier.md`](docs/swarm/review-classifier.md).
 - **`swarmctl/`** — swarm-level operator CLI, installed by the
   swarm-controller module on the host that runs the daemon. Runs as
   **root and acts directly** — it serves no socket, publishes no HTTP