refactor: 收敛渲染链路共享抽象

apps/server/tests/app.test.ts

@@ -287,6 +287,58 @@ describe("预览 API", () => {
     );
   });
 
+  it("缓存主题目录扫描并支持主动失效", async () => {
+    temporaryDirectory = await mkdtemp(join(tmpdir(), "md-to-pdf-theme-"));
+    const bundledRoot = join(temporaryDirectory, "bundled");
+    const localRoot = join(temporaryDirectory, "local");
+    const firstThemeRoot = join(localRoot, "first-theme");
+    const secondThemeRoot = join(localRoot, "second-theme");
+    await mkdir(bundledRoot, { recursive: true });
+    await mkdir(firstThemeRoot, { recursive: true });
+    await writeFile(
+      join(firstThemeRoot, "theme.json"),
+      JSON.stringify(localThemeManifest("first-theme")),
+      "utf8"
+    );
+    await writeFile(
+      join(firstThemeRoot, "theme.css"),
+      "#write { color: #333; }",
+      "utf8"
+    );
+
+    const registry = createThemeRegistry({
+      bundledRoot,
+      localRoot,
+      cacheTtlMs: 60_000
+    });
+    await expect(registry.list()).resolves.toHaveLength(1);
+
+    await mkdir(secondThemeRoot, { recursive: true });
+    await writeFile(
+      join(secondThemeRoot, "theme.json"),
+      JSON.stringify(localThemeManifest("second-theme")),
+      "utf8"
+    );
+    await writeFile(
+      join(secondThemeRoot, "theme.css"),
+      "#write { color: #666; }",
+      "utf8"
+    );
+    await expect(registry.list()).resolves.toHaveLength(1);
+
+    registry.invalidate();
+    await expect(registry.list()).resolves.toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({
+          manifest: expect.objectContaining({ id: "first-theme" })
+        }),
+        expect.objectContaining({
+          manifest: expect.objectContaining({ id: "second-theme" })
+        })
+      ])
+    );
+  });
+
   it("拒绝主题 CSS 导入外部地址", async () => {
     temporaryDirectory = await mkdtemp(join(tmpdir(), "md-to-pdf-theme-"));
     const bundledRoot = join(temporaryDirectory, "bundled");