fix(browser): address platform and port review

tests/unit/utils/browser/platform.test.ts

@@ -0,0 +1,17 @@
+import { describe, expect, it } from 'bun:test';
+import { getNodePlatformKey } from '../../../../src/utils/browser/platform';
+
+describe('browser platform helper', () => {
+  it('maps darwin explicitly', () => {
+    expect(getNodePlatformKey('darwin')).toBe('darwin');
+  });
+
+  it('maps win32 explicitly', () => {
+    expect(getNodePlatformKey('win32')).toBe('win32');
+  });
+
+  it('falls back to linux for other node platforms', () => {
+    expect(getNodePlatformKey('linux')).toBe('linux');
+    expect(getNodePlatformKey('freebsd')).toBe('linux');
+  });
+});