fix(release): markdownFiles skips what is not a file or a folder

CHANGELOG.md

@@ -7,6 +7,16 @@ Versions before 0.8.0 are in the [git tags](https://github.com/leemour/cli-core/
 Every entry says what changed as a caller sees it, why, and what to watch for — the rules are
 [`docs/dev/CONVENTIONS.md`](docs/dev/CONVENTIONS.md#the-changelog).
 
+## Unreleased
+
+### Fixed
+
+- **`cli-dev docs-check` and `markdownFiles` skip what is not a file or a folder.** A device or a
+  pipe named `*.md` used to be read, and the check crashed. Claude Code's Bash sandbox lays devices
+  over names in the working folder (`.claude/loop.md`, `.claude/skills`), so the check failed in
+  every agent session with the sandbox on. A symbolic link to a file is still listed; a link to a
+  folder is still not followed.
+
 ## 0.17.0 — 03.10.2026
 
 ### Changed — may break callers

src/release/markdown.ts

@@ -106,8 +106,11 @@ export const markdownFiles = (directory: string, skip: ReadonlySet<string> = new
     ? readdirSync(directory, { withFileTypes: true }).flatMap((entry) => {
         if (skip.has(entry.name)) return []
         const path = join(directory, entry.name)
-        if (entry.isDirectory()) return markdownFiles(path, skip)
-        return entry.name.endsWith(".md") ? [path] : []
+        // stat, not the entry's own type: Claude Code's sandbox mounts character devices over names
+        // like .claude/loop.md, and the directory listing still reports what lies underneath.
+        const stats = statSync(path, { throwIfNoEntry: false })
+        if (entry.isDirectory() && stats?.isDirectory()) return markdownFiles(path, skip)
+        return stats?.isFile() && entry.name.endsWith(".md") ? [path] : []
       })
     : []
 

src/release/release.test.ts

@@ -1,4 +1,5 @@
-import { mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from "node:fs"
+import { execFileSync } from "node:child_process"
+import { mkdirSync, mkdtempSync, readFileSync, rmSync, symlinkSync, writeFileSync } from "node:fs"
 import { tmpdir } from "node:os"
 import { dirname, join } from "node:path"
 import { afterEach, beforeEach, describe, expect, it } from "vitest"
@@ -168,6 +169,18 @@ describe("slug", () => {
   })
 })
 
+describe("markdownFiles", () => {
+  it.skipIf(process.platform === "win32")("lists files and links, not a special file with a .md name", () => {
+    const root = mkdtempSync(join(tmpdir(), "markdown-files-"))
+    writeFileSync(join(root, "README.md"), "# x\n")
+    symlinkSync(join(root, "README.md"), join(root, "linked.md"))
+    execFileSync("mkfifo", [join(root, "loop.md")])
+
+    expect(markdownFiles(root).sort()).toEqual([join(root, "README.md"), join(root, "linked.md")])
+    rmSync(root, { recursive: true, force: true })
+  })
+})
+
 describe("docsProblems", () => {
   let root: string
   const write = (path: string, text: string) => {