implement account lockout after 3 failed login attempts with 5-minute cooldown period

backend/internal/db/queries/query.sql

@@ -6,6 +6,25 @@ RETURNING *;
 -- name: GetUserByUsername :one
 SELECT * FROM users WHERE username = $1;
 
+-- name: ResetLoginFailures :exec
+UPDATE users
+SET failed_login_attempts = 0,
+    locked_until = NULL
+WHERE username = $1;
+
+-- name: RecordFailedLogin :one
+UPDATE users
+SET failed_login_attempts = CASE
+        WHEN failed_login_attempts + 1 >= 3 THEN 3
+        ELSE failed_login_attempts + 1
+    END,
+    locked_until = CASE
+        WHEN failed_login_attempts + 1 >= 3 THEN NOW() + INTERVAL '5 minutes'
+        ELSE locked_until
+    END
+WHERE username = $1
+RETURNING failed_login_attempts, locked_until;
+
 -- name: GetDeliveriesByDate :many
 SELECT * FROM deliveries WHERE date = $1;