Change cert renewal period from 30 to 60 days after issuance

acme.sh default --days is 30, which triggers renewal 60 days before
expiry. Setting --days 60 aligns with the common practice of renewing
30 days before the 90-day certificate expires.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

haproxy_mcp/tools/certificates.py

@@ -231,7 +231,7 @@ def _haproxy_issue_cert_impl(domain: str, wildcard: bool) -> str:
     cmd = [ACME_SH, "--issue", "--dns", "dns_cf", "-d", domain]
     if wildcard:
         cmd.extend(["-d", f"*.{domain}"])
-    cmd.extend(["--reloadcmd", reload_cmd])
+    cmd.extend(["--days", "60", "--reloadcmd", reload_cmd])
 
     try:
         logger.info("Issuing certificate for %s", domain)