The module is a rename (97% similar); everything else in the diff follows
from the move:
- stored_secret.rs: private `chain()` helper, the 8-line copy of the queue
crate's `chain` the module called as `crate::chain`; the queue crate's
public `chain` stays.
- stored_secret.rs: `Duration::from_mins(5)` in `MAX_REREAD_DELAY` is
unchanged moved code, not a new use.
- swarm-secret-client Cargo.toml: gains futures-util, tokio and tracing as
dependencies and tokio `test-util` plus tracing-subscriber as dev
dependencies; the module and its tests use them.
- swarm-queue-client Cargo.toml: drops futures-util and the tracing-subscriber
dev dependency, which only the moved module used; its tokio dev comment is
reworded to the tests that remain.
- Cargo.lock: the same dependency moves, nothing else.
- swarm-queue-client lib.rs: imports `swarm_secret_client::stored_secret`,
and its tests use a small local `Store` in place of the moved module's
test-only `Fake`, which is no longer reachable.
- callers (hive-c0re, swarm-builder, swarm-ci-metrics, swarm-claude-login,
swarm-controller, swarm-nats-auth, swarm-review-classifier): import path
only; no re-export is left behind.