Release 2026.9.27.1

The audit log (#64): every administrator change, admin sign-in and look
into someone else's data, recorded before it happens, chained per node
and checkable for tampering, exportable with a manifest, kept 2 years.

Locked accounts (#65, #66): an account that keeps receiving mail but
can't sign in and sends nothing on its own, handed to delegates at read,
organize or full, ending at a date when one is set.

Prepared Explain answers relabeled for this release; no setting changed
since 2026.9.27, so all 706 carry over.

crates/types/src/branding.rs

@@ -81,7 +81,7 @@ fn legacy_setting(name: &str, is_set: impl Fn(&str) -> bool) -> Option<String> {
 #[macro_export]
 macro_rules! brand_version {
     () => {
-        "2026.9.27"
+        "2026.9.27.1"
     };
 }