GO-2026-4644 Caddy's vars_regexp double-expands user input, leaking env vars and files in github.com/caddyserver/caddy

Caddy's varsregexp double-expands user input, leaking env vars and files in github.com/caddyserver/caddy...

GO-2026-4538 Caddy MatchPath %xx branch skips case normalization in github.com/caddyserver/caddy/v2

Caddy MatchPath %xx branch skips case normalization in github.com/caddyserver/caddy/v2...