Updated default stage

src/app.zig

@@ -13,6 +13,16 @@ const Self = @This();
 /// Default app stages
 /// ----------------------------------------------------
 pub const stage = struct {
+    // --- BEGIN FRAME ---
+    pub const pre_begin_frame = struct {};
+    pub const begin_frame = struct {};
+    pub const post_begin_frame = struct {};
+
+    // --- END FRAME ---
+    pub const pre_end_frame = struct {};
+    pub const end_frame = struct {};
+    pub const post_end_frame = struct {};
+
     // --- INIT ---
     pub const pre_init = struct {};
     pub const init = struct {};