fix: use ~/.codeium/windsurf as Windsurf global config dir (#1856)

tests/windsurf-install.test.cjs

@@ -0,0 +1,52 @@
+process.env.GSD_TEST_MODE = '1';
+
+const { describe, test, beforeEach, afterEach } = require('node:test');
+const assert = require('node:assert/strict');
+const os = require('os');
+const path = require('path');
+
+const { getGlobalDir } = require('../bin/install.js');
+
+describe('getGlobalDir (Windsurf)', () => {
+  let originalWindsurfConfigDir;
+
+  beforeEach(() => {
+    originalWindsurfConfigDir = process.env.WINDSURF_CONFIG_DIR;
+    delete process.env.WINDSURF_CONFIG_DIR;
+  });
+
+  afterEach(() => {
+    if (originalWindsurfConfigDir !== undefined) {
+      process.env.WINDSURF_CONFIG_DIR = originalWindsurfConfigDir;
+    } else {
+      delete process.env.WINDSURF_CONFIG_DIR;
+    }
+  });
+
+  test('returns ~/.codeium/windsurf with no env var or explicit dir', () => {
+    const result = getGlobalDir('windsurf');
+    assert.strictEqual(result, path.join(os.homedir(), '.codeium', 'windsurf'));
+  });
+
+  test('returns explicit dir when provided', () => {
+    const result = getGlobalDir('windsurf', '/custom/windsurf-path');
+    assert.strictEqual(result, '/custom/windsurf-path');
+  });
+
+  test('respects WINDSURF_CONFIG_DIR env var', () => {
+    process.env.WINDSURF_CONFIG_DIR = '~/custom-windsurf';
+    const result = getGlobalDir('windsurf');
+    assert.strictEqual(result, path.join(os.homedir(), 'custom-windsurf'));
+  });
+
+  test('explicit dir takes priority over WINDSURF_CONFIG_DIR', () => {
+    process.env.WINDSURF_CONFIG_DIR = '~/from-env';
+    const result = getGlobalDir('windsurf', '/explicit/path');
+    assert.strictEqual(result, '/explicit/path');
+  });
+
+  test('does not break other runtimes', () => {
+    assert.strictEqual(getGlobalDir('claude'), path.join(os.homedir(), '.claude'));
+    assert.strictEqual(getGlobalDir('codex'), path.join(os.homedir(), '.codex'));
+  });
+});