Function readFile

Support/SingleFileLibs/javascript/cli.js:100–102

(_ref, path)

      return rel;
    },
    async readFile(_ref, path) {
      return await readText(join(repoRoot, path));
    },
    async getVersionString(_ref) {
      // Try to mimic Python version: <latest tag> (<short sha>)
      // For simplicity here, return just the short HEAD sha via git, falling back to 'unknown'