arXiv to BibTeX - fixes the doubled "arXiv:" (opens in new tab)

arXiv's API doesn't send CORS headers, so a genuinely browser-only tool can't talk to it directly - this routes through a small proxy (a cPanel PHP passthrough, not a third-party service) that hits arXiv's API and parses the result. The proxy doesn't log bibliographic content, caches by ID hash (30 days for versioned IDs since those are immutable, 7 days otherwise), and rate-limits per IP. The actual bug this fixes: most converters emit eprint = {arXiv:1706.03762}, but biblatex's \eprint macr...