style: cargo fmt across Phase 3.5 changes

Pure formatting pass — no behavior changes. Catches the line-wrapping
drift across the new authz / api_keys / middleware / handler edits
that piled up during the implementation.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/shared/src/auth.rs

@@ -196,7 +196,11 @@ mod tests {
 
     #[test]
     fn instance_role_round_trip() {
-        for role in [InstanceRole::Owner, InstanceRole::Admin, InstanceRole::Member] {
+        for role in [
+            InstanceRole::Owner,
+            InstanceRole::Admin,
+            InstanceRole::Member,
+        ] {
             assert_eq!(InstanceRole::from_db_str(role.as_str()), Some(role));
         }
         assert_eq!(InstanceRole::from_db_str("bogus"), None);