fix: decode UTF-16LE shell output on Windows

[tsmithsz]

Problem

On Windows we launch shell commands through cmd.exe /c. cmd.exe writes legacy code‑page bytes.
Because our ExecuteBash tool always assumed UTF‑8, any non‑ASCII characters in the output were being mis‑decoded and displayed as ??. This affected customers

Solution

• Invoke cmd with /u on Windows: Forces UTF‑16 LE encoding (this is how Windows handles Unicode) for all output written to the process pipes, independent of the console code‑page.
• Heuristic decoder:
  • Re‑creates the raw bytes from the received string (Buffer.from(text, 'binary')).
  • Detects UTF‑16 LE by checking whether every odd byte in the first 32 bytes is 0x00.
  • Decodes with buffer.toString('utf16le') when the pattern matches, otherwise falls back to UTF‑8.

Testing

Before Fix:

After Fix:

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.