MiniMax Speech 2.8 helper

1. **Install dependencies.** Run `pip install requests` in the environment that will execute the script. The CLI talks to MiniMax's REST API, so you only need the `requests` library on top of Python 3.11+. 2. **Set your MiniMax credential.** Export `MINIMAX_API_KEY` with the API key the user promised to supply. The script will refuse to run without it. 3. **Use the bundled CLI.** `scripts/minimax_tts.py` exposes two subcommands: - `tts`: calls `POST https://api.minimax.io/v1/t2a_v2` (Speech 2.8