fix(text): support piped messages on Windows

- use the standard input file descriptor instead of /dev/stdin
- reuse the shared file-or-stdin reader in text chat

packages/core/src/utils/fs.ts

@@ -1,5 +1,7 @@
 import { readFileSync } from "fs";
 
+const STDIN_FILE_DESCRIPTOR = 0;
+
 export function readTextFromPathOrStdin(path: string): string {
-  return readFileSync(path === "-" ? "/dev/stdin" : path, "utf-8");
+  return readFileSync(path === "-" ? STDIN_FILE_DESCRIPTOR : path, "utf-8");
 }

packages/core/src/utils/index.ts

@@ -2,6 +2,7 @@ export { generateFilename } from "./filename.ts";
 export { resolveOutputDir } from "./output-dir.ts";
 export { maskToken } from "./token.ts";
 export { stripUndefined } from "./object.ts";
+export { readTextFromPathOrStdin } from "./fs.ts";
 export {
   parseBooleanValue,
   parseOptionalBooleanValue,