Preserve instruction symlink guard through fs seam

packages/fs/fs-local/tests/fsio.spec.ts

@@ -14,6 +14,7 @@ import {
   applyLiteralEdit,
   listDirectory,
   probe,
+  probeNoFollow,
   readForEdit,
   readWholeText,
   resolveLocalTarget,
@@ -146,6 +147,27 @@ describe('probe', () => {
   })
 })
 
+describe('probeNoFollow', () => {
+  it('reports symlinks without following them', async () => {
+    const real = join(dir, 'real.txt')
+    const link = join(dir, 'link.txt')
+    await writeFile(real, 'hi')
+    await symlink(real, link)
+
+    expect((await probeNoFollow(real))?.type).toBe('file')
+    const linkInfo = await probeNoFollow(link)
+    expect(linkInfo?.type).toBe('symlink')
+    expect(typeof linkInfo?.version).toBe('string')
+    expect(linkInfo?.size).toBeGreaterThan(0)
+  })
+
+  it('returns null for a missing path or a file-valued ancestor path segment', async () => {
+    expect(await probeNoFollow(join(dir, 'missing'))).toBeNull()
+    await writeFile(join(dir, 'afile'), 'i am a file')
+    expect(await probeNoFollow(join(dir, 'afile', 'child.txt'))).toBeNull()
+  })
+})
+
 describe('listDirectory', () => {
   it('lists direct children in stable order without reading content', async () => {
     const root = join(dir, 'skills')