feat: Add certificate management tools (6 new MCP tools)

New tools for SSL/TLS certificate management via acme.sh:
- haproxy_list_certs: List all certificates with expiry info
- haproxy_cert_info: Get detailed certificate info (expiry, issuer, SANs)
- haproxy_issue_cert: Issue new certificate via Cloudflare DNS validation
- haproxy_renew_cert: Renew specific certificate (with force option)
- haproxy_renew_all_certs: Renew all certificates due for renewal
- haproxy_delete_cert: Delete certificate from acme.sh and HAProxy

Features:
- Automatic PEM deployment to HAProxy certs directory
- HAProxy hot-reload after certificate changes (USR2 signal)
- Cloudflare DNS validation with CF_Token support
- Wildcard certificate support

Total MCP tools: 22 → 28

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

haproxy_mcp/tools/__init__.py

@@ -5,6 +5,7 @@ from .servers import register_server_tools
 from .health import register_health_tools
 from .monitoring import register_monitoring_tools
 from .configuration import register_config_tools
+from .certificates import register_certificate_tools
 
 
 def register_all_tools(mcp):
@@ -18,3 +19,4 @@ def register_all_tools(mcp):
     register_health_tools(mcp)
     register_monitoring_tools(mcp)
     register_config_tools(mcp)
+    register_certificate_tools(mcp)