fix(test): evaluate Windows platform check lazily for CI portability

isWindows was a module-level constant evaluated at import time, so
vi.stubGlobal('navigator', ...) in tests took effect too late and the
value froze to the host platform - breaking the Windows path
normalization tests on Linux/macOS CI runners.

- replace the isWindows constant with an isWindowsPlatform() function
  evaluated per call
- anchor the platform regex (^win) so 'Darwin' is not misdetected
- give the test navigator stub a realistic platform + userAgent pair

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: MidnightCrowing

src/utils/path.ts

@@ -2,11 +2,16 @@ const WINDOWS_VERBATIM_UNC_RE = /^\\\\\?\\UNC\\/
 const WINDOWS_VERBATIM_RE = /^\\\\\?\\/
 const TRAILING_SLASH_RE = /\/+$/
 
-/** 当前是否运行在 Windows 上(路径比较时大小写不敏感)。 */
-export const isWindows = (() => {
-  // 优先使用 userAgent/platform(Tauri WebView 下可靠)
+/**
+ * 当前是否运行在 Windows 上(路径比较时大小写不敏感)。
+ * 必须在调用时求值而非模块加载时缓存:测试通过 stubGlobal 替换
+ * navigator,模块级常量会在 stub 生效前被锁死为宿主平台的值。
+ */
+export function isWindowsPlatform(): boolean {
+  // 优先使用 platform/userAgent(Tauri WebView 下可靠)。
+  // 用 ^win 锚定避免 'Darwin' 误匹配。
   if (typeof navigator !== 'undefined') {
-    if (navigator.platform && /win/i.test(navigator.platform))
+    if (navigator.platform && /^win/i.test(navigator.platform))
       return true
     if (/Windows/.test(navigator.userAgent))
       return true
@@ -20,7 +25,7 @@ export const isWindows = (() => {
   catch {
     return false
   }
-})()
+}
 
 /** 去除 Windows canonicalize 产生的 verbatim 前缀(`\\?\` / `\\?\UNC\`)。 */
 export function stripWindowsVerbatimPrefix(path: string) {
@@ -35,5 +40,5 @@ export function stripWindowsVerbatimPrefix(path: string) {
  */
 export function normalizePathKey(path: string) {
   const normalized = stripWindowsVerbatimPrefix(path).trim().replaceAll('\\', '/').replace(TRAILING_SLASH_RE, '')
-  return isWindows ? normalized.toLowerCase() : normalized
+  return isWindowsPlatform() ? normalized.toLowerCase() : normalized
 }

tests/projectsStore.test.ts

@@ -18,7 +18,10 @@ function createMemoryStorage() {
 describe('projectsStore', () => {
   beforeEach(() => {
     setActivePinia(createPinia())
-    vi.stubGlobal('navigator', { userAgent: 'Windows' })
+    vi.stubGlobal('navigator', {
+      platform: 'Win32',
+      userAgent: 'Mozilla/5.0 (Windows NT 10.0; Win64; x64)',
+    })
     vi.stubGlobal('window', {
       localStorage: createMemoryStorage(),
       api: {