diff --git a/package-lock.json b/package-lock.json
index 851641a..a6400f8 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1380,6 +1380,7 @@
       "version": "13.0.3",
       "resolved": "https://registry.npmjs.org/better-sqlite3/-/better-sqlite3-13.0.3.tgz",
       "integrity": "sha512-RbOBxmLBG8uvFUc15X9+9SFemKcQ0WBuISBVkpuiaUB2qblC8UWlHEjdWVoZ8AdhSwmoEgsiXKfopX0CQxaACQ==",
+      "hasInstallScript": true,
       "license": "MIT",
       "dependencies": {
         "node-addon-api": "^8.0.0"
diff --git a/package.json b/package.json
index dc36293..326dd86 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,7 @@
     "api": "tsx server/index.ts",
     "build": "tsc -b && vite build",
     "typecheck:server": "tsc -p tsconfig.server.json",
-    "test": "tsx --test packages/game-core/index.test.ts",
+    "test": "tsx --test packages/game-core/index.test.ts src/ui-format.test.ts",
     "preview": "vite preview --host"
   },
   "dependencies": {
diff --git a/packages/game-core/index.test.ts b/packages/game-core/index.test.ts
index 1dc7c3a..e02ab85 100644
--- a/packages/game-core/index.test.ts
+++ b/packages/game-core/index.test.ts
@@ -1,6 +1,6 @@
 import assert from "node:assert/strict";
 import test from "node:test";
-import { createPuzzle, dailyGame, replay, simulateFlight } from "./index.js";
+import { createPuzzle, dailyGame, replay, simulateFlight, stackBlockX } from "./index.js";
 
 test("same seed creates the same puzzle", () => {
   assert.deepEqual(createPuzzle("reaction", "abc"), createPuzzle("reaction", "abc"));
@@ -8,7 +8,7 @@ test("same seed creates the same puzzle", () => {
 });
 
 test("daily rotation always selects a ranked challenge", () => {
-  const ranked = new Set(["reaction", "color", "whack", "flight", "pop", "memory"]);
+  const ranked = new Set(["reaction", "color", "whack", "flight", "pop", "memory", "stack"]);
   for (const day of ["2026-09-01", "2026-09-02", "2026-09-03", "2026-09-04", "2026-09-05"]) assert.equal(ranked.has(dailyGame(day)), true);
 });
 
@@ -99,16 +99,6 @@ test("flight: a bird that never flaps falls to the ground and cannot finish", ()
   assert.equal(noFlap.completed, false);
 });
 
-test("flight: a bird that never flaps falls to the ground and cannot finish", () => {
-  const idle = replay("flight", "seed-flight", [{ t: 8000, type: "key", value: "flap" }]);
-  assert.equal(idle.valid, true);
-  assert.equal(idle.completed, false);
-  assert.equal(idle.score, 0);
-  // Even a late flap cannot grant a passed pipe once the bird hits the floor.
-  const noFlap = replay("flight", "seed-flight", []);
-  assert.equal(noFlap.completed, false);
-});
-
 test("flight: live horizon verdict never projects a future ground death", () => {
   const puzzle = createPuzzle("flight", "seed-flight");
   if (puzzle.gameId !== "flight") return;