Fixes update checks failing with a bare HTTP 403 on shared networks.
Reported by @pedroknigge — the update check was hitting GitHub's unauthenticated REST API, capped at 60 requests/hour per IP, shared with anything else on that network talking to api.github.com. Easy to hit on a home or office NAT without Quill being the only thing responsible.
The check now uses the ordinary /releases/latest web redirect instead, which carries no rate-limit headers at all. The REST API is now only a fallback, and if it's ever the one that fails, a real rate limit shows as "GitHub rate limit reached — try again in Nm" instead of a bare status code.
Reproduced for real before fixing: burned through the actual quota from this machine's IP until the API returned 403, then confirmed the update check still succeeds under that exact condition.
curl -fsSL https://raw.githubusercontent.com/xfreeze2/quill/main/install.sh | bash