docs(#3422): the user store is one file, not two

Six places asserted the old design as fact, and none of them mention the
change by name -- the class of doc breakage that is found by asking what
a diff made untrue, not by grepping for a feature:

- swarmctl/README.md and swarm-authelia-bridge/README.md both described
  their own private canonical store. The bridge's "known limitation"
  section described the seam as unsolved; it is what this fixes, so it
  becomes what both writers must uphold instead.
- docs/swarm/{sso,ui,secrets}.md described a rendered artifact.
- The repo CLAUDE.md entry for swarmctl said the same.
- docs/tools/swarmctl-cli.md is regenerated (CI diffs it against the
  clap tree), picking up the removed --store flag.

Operator-facing where it is read: the hand-editing consequence (values
survive a rewrite, comments do not) is stated in sso.md, where an
operator is being told to edit the file, rather than only in a module doc.

swarmctl/src/users.rs

@@ -406,9 +406,9 @@ users:
         );
     }
 
-    /// The #3414 property, moved from the renderer to the write path along
-    /// with the synthesis itself: a user who supplied an address keeps it,
-    /// and no invented one appears beside it.
+    /// The earlier missing-email property, moved from the renderer to the
+    /// write path along with the synthesis itself: a user who supplied an
+    /// address keeps it, and no invented one appears beside it.
     #[test]
     fn a_supplied_email_is_never_replaced_by_the_synthetic_one() {
         let mut u = user("$argon2id$x");