docs(swarm-authelia-bridge-sock): the bridge reads and writes users.yml, there is no canonical json

The wire crate's module doc and its README both said the bridge "owns both
users.json (canonical) and rendering users.yml internally". That store was
removed — swarm-authelia-bridge/src/store.rs is explicit that users.yml *is*
the store — so both sentences described a file that does not exist, in the
one place a reader goes to learn what the API is for.

The paragraph's actual argument (per-operation rather than
wholesale-replace) is untouched; only the mechanism it cites was wrong.

swarm-authelia-bridge-sock/src/lib.rs

@@ -20,11 +20,10 @@
 //! the file it writes. Fully ordinary permissions, no capabilities, no root.
 //!
 //! **Per-operation, not wholesale-replace.** [`BridgeRequest::EnsureAgentIdentity`]
-//! asks for one user to exist; the bridge owns both `users.json` (canonical)
-//! and rendering `users.yml` internally. A caller never sends rendered YAML
-//! or a file blob — that would invite a last-writer-wins race between
-//! independent callers and duplicate the rendering logic on both sides of
-//! the wire.
+//! asks for one user to exist; the bridge reads `users.yml`, changes what the
+//! request named, and writes it back. A caller never sends rendered YAML or a
+//! file blob — that would invite a last-writer-wins race between independent
+//! callers and duplicate the rendering logic on both sides of the wire.
 
 use serde::{Deserialize, Serialize};