fix: backend code review — atomic writes, lock ordering, validation

1 files changed, 4 insertions, 0 deletions

diff --git a/src-tauri/src/timer.rs b/src-tauri/src/timer.rs
index 7e26ad8..44e5999 100644
--- a/src-tauri/src/timer.rs
+++ b/src-tauri/src/timer.rs
@@ -7,6 +7,10 @@ use tauri::{AppHandle, Emitter};
 use crate::state::{TimerPhase, TimerState};
 use crate::storage::{self, AppData};
 
+// LOCK ORDERING: When acquiring multiple locks, always take timer_state
+// before app_data to prevent deadlock. Never acquire app_data first
+// while timer_state is not held.
+
 // ── Event payloads ──────────────────────────────────────────────────────────
 
 #[derive(Clone, Serialize)]