test: make five suites Windows-runner clean

First ci-windows run exposed four platform assumptions in the fixtures:

- smoke: the scratch repo inherited the runner's system-wide
  core.autocrlf=true (Git for Windows default), so every index restore
  smudged LF to CRLF and broke the byte-exact assertions — pin
  core.autocrlf=false in the fixture (eol policy is not what these
  destructive-op tests are about).
- git / git-worktree: Windows TEMP is the 8.3 short form
  (C:\Users\RUNNER~1\...) while git reports long paths, and
  realpathSync does not expand 8.3 aliases — switch the canonicalizer
  to realpathSync.native (libuv resolves via GetFinalPathNameByHandle,
  which does); same trick as the existing macOS /var workaround.
- bundle-route: the ETag memo revalidates on stat (mtime+size) and
  Windows updates file timestamps lazily, so the equal-size rewrite
  still looked unchanged — change the length too.
- market-manifest: GNU tar (Git Bash) reads the drive-letter colon of
  absolute Windows paths as a remote-host spec — run it from the pack
  dir with the bare tarball name instead.

tests/bundle-route.spec.ts

@@ -84,7 +84,12 @@ describe('/sidebar/bundle route', () => {
     try {
       const first = fakeRes()
       await handler(req('GET', '/sidebar/bundle/editor.js'), first as unknown as ServerResponse)
-      writeFileSync(join(dir, 'client-editor.js'), 'window.__ModuleLoader__ && 1;')
+      // The rewrite must change the LENGTH too: the ETag memo revalidates on
+      // stat (mtime+size), and Windows updates file timestamps lazily — an
+      // equal-size rewrite right after the first read can still look
+      // unchanged (stale 304). A size delta busts the memo deterministically
+      // on every platform.
+      writeFileSync(join(dir, 'client-editor.js'), 'window.__ModuleLoader__ && 1; // rotated')
       const second = fakeRes()
       await handler(req('GET', '/sidebar/bundle/editor.js', { 'if-none-match': first.headers.etag! }), second as unknown as ServerResponse)
       expect(second.status).toBe(200)

tests/git-worktree.spec.ts

@@ -68,8 +68,11 @@ describe('linked Git worktrees', () => {
       git(main, ['worktree', 'add', '-q', '-b', 'agent', agent])
       writeFileSync(join(agent, 'tracked.txt'), 'changed by agent\n')
       // macOS tmpdir() keeps the /var symlink while git reports the resolved
-      // /private/var prefix — canonicalize every path handed to git APIs.
-      const agentPath = realpathSync(agent)
+      // /private/var prefix; on Windows TEMP is often the 8.3 short form
+      // (C:\Users\RUNNER~1\...) while git reports the long path. The NATIVE
+      // realpath resolves both aliasings (libuv's GetFinalPathNameByHandle
+      // expands 8.3 names) — canonicalize every path handed to git APIs.
+      const agentPath = realpathSync.native(agent)
 
       const listed = await worktrees(main)
       expect(listed).toHaveLength(2)
@@ -87,7 +90,7 @@ describe('linked Git worktrees', () => {
       rmSync(agent, { recursive: true, force: true })
       const remaining = await worktrees(main)
       expect(remaining).toHaveLength(1)
-      expect(resolve(remaining[0]!.path)).toBe(resolve(realpathSync(main)))
+      expect(resolve(remaining[0]!.path)).toBe(resolve(realpathSync.native(main)))
       expect(remaining[0]!.current).toBe(true)
       await expect(resolveWorktree(main, agentPath)).rejects.toThrow('unknown linked worktree')
     } finally {

tests/git.spec.ts

@@ -11,8 +11,12 @@ 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))
+// /private/var prefix; on Windows TEMP is often the 8.3 short form
+// (C:\Users\RUNNER~1\...) while git reports the long path. The NATIVE
+// realpath resolves both aliasings (libuv canonicalizes on Windows via
+// GetFinalPathNameByHandle, which expands 8.3 names) — canonicalize both
+// sides before comparing.
+const canonical = (path: string): string => normalizePath(realpathSync.native(path))
 
 describe('git parsing', () => {
   it('discovers and selects direct child repositories under a workspace directory', async () => {

tests/market-manifest.spec.ts

@@ -57,7 +57,10 @@ function packedManifest(): Record<string, unknown> {
     // spawn directly (ENOENT). Run it through the shell so the same call
     // works on every platform; `tar` is available on all supported OSes.
     execFileSync('pnpm', ['pack', '--pack-destination', dir], { cwd: ROOT, stdio: 'pipe', shell: process.platform === 'win32' })
-    execFileSync('tar', ['-xzf', join(dir, `${pkg.name}-${pkg.version}.tgz`), '-C', dir, 'package/package.json'], { stdio: 'pipe' })
+    // Never hand tar an absolute Windows path: Git Bash's GNU tar reads the
+    // drive-letter colon as a remote-host spec ("Cannot connect to C:").
+    // Run it from the pack dir with the bare tarball name instead.
+    execFileSync('tar', ['-xzf', `${pkg.name}-${pkg.version}.tgz`, 'package/package.json'], { cwd: dir, stdio: 'pipe' })
     return JSON.parse(readFileSync(join(dir, 'package/package.json'), 'utf8')) as Record<string, unknown>
   } finally {
     rmSync(dir, { recursive: true, force: true })

tests/smoke.spec.ts

@@ -409,6 +409,12 @@ describe('git destructive operations (scratch repository)', () => {
   const makeScratchRepo = (): string => {
     const dir = mkdtempSync(join(tmpdir(), 'dsh-sidebar-git-'))
     gitRun(dir, ['init', '-q'])
+    // Pin the eol policy: Git for Windows defaults to core.autocrlf=true
+    // (system gitconfig on the CI runner, and many dev machines), which
+    // smudges LF→CRLF on every index restore and breaks the byte-exact
+    // assertions below. The destructive-op behavior under test is orthogonal
+    // to the machine's eol policy.
+    gitRun(dir, ['config', 'core.autocrlf', 'false'])
     gitRun(dir, ['checkout', '-q', '-b', 'main'])
     writeFileSync(join(dir, 'a.txt'), 'one\ntwo\nthree\n')
     gitRun(dir, ['add', '-A'])