fix(test): 测试间状态串台与 macOS 临时目录路径导致的用例失败

两处既有测试基建问题（在慢 runner 的 CI 上表现为 free-window 用例
间歇性失败，阻塞 PR 合并）：

- free-window/sidebar-crash/bottom-auto-terminal 三个 spec 共用 session
  id 's1'：store 会按 200ms 防抖把每会话状态持久化到
  localStorage['dsh-sidebar:v1:s1']，前一个用例的迟写（drop 点 400,300
  → 浮窗 left=205）被下一用例 setSession 恢复，新浮窗断言（期望 317）
  被 querySelector 拿到的旧窗口炸掉——用例间隔是否超过 200ms 决定成
  败，本地快时常过、CI 慢必挂。修复：挂载 helper 缺省生成唯一
  session id（持久化往返用例显式传固定 id），afterEach 在 unstub 之后
  清 localStorage 兜底
- git/git-worktree 两个用例在 macOS 上必挂：tmpdir() 返回 /var 符号
  链接而 git 报告解析后的 /private/var 前缀，路径比较与
  resolveWorktree 的恒等匹配失配（CI 的 Linux 路径规范所以一直绿）。
  修复：期望值与传入 git API 的路径统一 realpathSync 规范化

本地全量 vitest 963 通过 0 失败（此前 free-window 间歇 0~2 失败 +
git 2 个环境性失败）；free-window 单文件连跑 8 次稳定。

tests/git.spec.ts

@@ -1,5 +1,5 @@
 import { execFile, execFileSync } from 'node:child_process'
-import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'node:fs'
+import { mkdirSync, mkdtempSync, realpathSync, rmSync, writeFileSync } from 'node:fs'
 import { mkdir, mkdtemp, rm } from 'node:fs/promises'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
@@ -10,6 +10,9 @@ import { parseLogLines, parsePorcelainZ, repoRoots, status } from '../src/git.ts
 
 const execFileAsync = promisify(execFile)
 const normalizePath = (path: string): string => path.replaceAll('\\', '/')
+// macOS tmpdir() is the /var symlink while git reports the resolved
+// /private/var prefix — canonicalize both sides before comparing.
+const canonical = (path: string): string => normalizePath(realpathSync(path))
 
 describe('git parsing', () => {
   it('discovers and selects direct child repositories under a workspace directory', async () => {
@@ -23,11 +26,11 @@ describe('git parsing', () => {
         execFileAsync('git', ['-C', second, 'init']),
       ])
 
-      await expect(repoRoots(workspace)).resolves.toEqual([normalizePath(first), normalizePath(second)])
-      await expect(status(workspace, normalizePath(second))).resolves.toMatchObject({
+      await expect(repoRoots(workspace)).resolves.toEqual([canonical(first), canonical(second)])
+      await expect(status(workspace, canonical(second))).resolves.toMatchObject({
         isRepo: true,
-        root: normalizePath(second),
-        repositories: [normalizePath(first), normalizePath(second)],
+        root: canonical(second),
+        repositories: [canonical(first), canonical(second)],
       })
     } finally {
       await rm(workspace, { recursive: true, force: true })