[Security] Your minimax API key was committed to this repo

Hey! Just a heads-up -- I ran a scan and it looks like an API key got committed to this repo, and it's still active.

| Detail | Value |
|--------|-------|
| Provider | minimax |
| File | `.env` |
| Source | https://github.com/decentralized-identity/universal-resolver/blob/7ffae961/.env |

### What's the risk?

The key is still live -- anyone who comes across it can use it, burning through your credits or quota.

### What to do:

1. **Revoke** the key in your minimax dashboard
2. Generate a new key and swap it in
3. Delete the key from the committed file and add `.env` to `.gitignore`
4. Check your minimax usage logs for anything suspicious
5. Scrub the key from git history with `git filter-branch` or BFG

Once you've sorted it out, just close this issue.

---

This is a free public-service scan. If it helped, you can buy me a coffee at https://ko-fi.com/cheeseup (no pressure at all).

Start with the committed .env file and revoke the exposed minimax key in the provider dashboard before making repository changes. Remove the key, add .env to .gitignore, generate and swap in a replacement, then scrub the key from git history with git filter-branch or BFG. Done means the old key is revoked, usage logs have been checked, and the secret is absent from the file and history.

Written by the indexing model from the issue text.