library: HTTPS via Caddy (install.sh --domain [--lan-tls]) so the live camera works; real visitor address behind a proxy; camera permission header

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013wi3ZSot4XbUViwRFgLpRf

library/.gitignore

@@ -3,3 +3,6 @@
 # Extra CA certificates dropped in for building behind a proxy
 koha/certs/*.crt
 quickadd/certs/*.crt
+# Generated by install.sh --domain
+Caddyfile
+caddy-root.crt