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/manager-core/src/app_members_repo.rs

@@ -19,10 +19,7 @@ pub enum AppMembersRepositoryError {
     Db(#[from] sqlx::Error),
 
     #[error("membership row not found: app={app_id}, user={user_id}")]
-    NotFound {
-        app_id: AppId,
-        user_id: AdminUserId,
-    },
+    NotFound { app_id: AppId, user_id: AdminUserId },
 
     #[error("invalid app_role stored in DB: {0}")]
     InvalidRole(String),