fix(ci): resolve macOS vitest worker crash (vitest#8564)

- Add NODE_OPTIONS memory limit for macOS CI (like Windows)
- Use singleFork mode on macOS CI to avoid worker termination crash
- All tests pass but workers crashed at teardown due to known vitest bug

.github/workflows/ci.yml

@@ -278,6 +278,8 @@ jobs:
   checks-macos:
     if: github.event_name == 'pull_request'
     runs-on: macos-latest
+    env:
+      NODE_OPTIONS: --max-old-space-size=4096
     strategy:
       fail-fast: false
       matrix:

vitest.config.ts

@@ -6,6 +6,7 @@ import { defineConfig } from "vitest/config";
 const repoRoot = path.dirname(fileURLToPath(import.meta.url));
 const isCI = process.env.CI === "true" || process.env.GITHUB_ACTIONS === "true";
 const isWindows = process.platform === "win32";
+const isMacOS = process.platform === "darwin";
 const localWorkers = Math.max(4, Math.min(16, os.cpus().length));
 const ciWorkers = isWindows ? 2 : 3;
 
@@ -19,6 +20,8 @@ export default defineConfig({
     testTimeout: 120_000,
     hookTimeout: isWindows ? 180_000 : 120_000,
     pool: "forks",
+    // Use singleFork on macOS CI to avoid vitest worker crash (vitest#8564)
+    poolOptions: isMacOS && isCI ? { forks: { singleFork: true } } : undefined,
     maxWorkers: isCI ? ciWorkers : localWorkers,
     include: [
       "src/**/*.test.ts",