fix: WAL mode + busy_timeout for SQLite, fix rate limiter TOCTOU race

crates/presentation/src/main.rs

@@ -48,7 +48,9 @@ async fn wire_dependencies() -> anyhow::Result<AppState> {
     let database_url = std::env::var("DATABASE_URL").context("DATABASE_URL must be set")?;
     let opts = SqliteConnectOptions::from_str(&database_url)
         .context("Invalid DATABASE_URL")?
-        .create_if_missing(true);
+        .create_if_missing(true)
+        .journal_mode(sqlx::sqlite::SqliteJournalMode::Wal)
+        .busy_timeout(std::time::Duration::from_secs(5));
     let pool = SqlitePool::connect_with(opts)
         .await
         .context("Failed to connect to SQLite database")?;

crates/presentation/src/routes.rs

@@ -35,14 +35,15 @@ impl RateLimiter {
             .unwrap_or_default()
             .as_secs()
             / 60;
-        let prev = self.window.load(Ordering::Relaxed);
+        let prev = self.window.load(Ordering::Acquire);
         if now != prev {
-            self.window.store(now, Ordering::Relaxed);
-            self.count.store(1, Ordering::Relaxed);
-            true
-        } else {
-            self.count.fetch_add(1, Ordering::Relaxed) + 1 <= self.limit
+            // compare_exchange ensures only one thread wins the window reset
+            if self.window.compare_exchange(prev, now, Ordering::AcqRel, Ordering::Relaxed).is_ok() {
+                self.count.store(1, Ordering::Release);
+                return true;
+            }
         }
+        self.count.fetch_add(1, Ordering::Relaxed) + 1 <= self.limit
     }
 }