fix: normalize ambience loudness for v0.2.5

tests/audio-integrity.test.ts

@@ -0,0 +1,44 @@
+// @vitest-environment node
+import { readFileSync } from "node:fs";
+import { expect, it } from "vitest";
+import { verifyAudioAsset } from "../src/audio/integrity";
+
+// 신뢰 기준은 JS 번들에 고정한 manifest다. 요청 파일이 자기 해시를 선언할 수 없다.
+it("109개 승인 WAV만 SHA-256·bytes·형식 검증을 통과한다", async () => {
+  let count = 0;
+  for (const directory of ["audio", "ambience"]) {
+    const manifest = JSON.parse(
+      readFileSync(`public/${directory}/manifest.json`, "utf8"),
+    );
+    for (const entry of manifest.files) {
+      const bytes = Uint8Array.from(
+        readFileSync(`public/${directory}/${entry.file}`),
+      ).buffer;
+      await expect(
+        verifyAudioAsset(`/${directory}/${entry.file}?v=0.2.5`, bytes),
+      ).resolves.toBeUndefined();
+      count++;
+    }
+  }
+  expect(count).toBe(109);
+});
+
+it("변조·다른 파일·외부 URL·이전 캐시·축약 응답은 decode 전에 거부한다", async () => {
+  const bytes = Uint8Array.from(readFileSync("public/ambience/street.wav"));
+  for (const url of [
+    "/ambience/rain.wav?v=0.2.5",
+    "/ambience/street.wav?v=0.2.3",
+    "https://external.example/ambience/street.wav?v=0.2.5",
+    "/ambience/unknown.wav?v=0.2.5",
+  ]) {
+    await expect(verifyAudioAsset(url, bytes.slice().buffer)).rejects.toThrow();
+  }
+  const corrupt = bytes.slice();
+  corrupt[100] = corrupt[100]! ^ 1;
+  await expect(
+    verifyAudioAsset("/ambience/street.wav?v=0.2.5", corrupt.buffer),
+  ).rejects.toThrow();
+  await expect(
+    verifyAudioAsset("/ambience/street.wav?v=0.2.5", bytes.slice(0, -2).buffer),
+  ).rejects.toThrow();
+});