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>

CLAUDE.md

@@ -241,7 +241,7 @@ Returns backend server status for a specific domain:
 
 **Status values:** `healthy` (all UP), `degraded` (partial UP), `down` (all DOWN), `no_servers`
 
-## MCP Tools (22 total)
+## MCP Tools (28 total)
 
 ### Domain Management
 | Tool | Description |
@@ -285,6 +285,16 @@ Returns backend server status for a specific domain:
 | `haproxy_save_state` | Save server state to disk (legacy) |
 | `haproxy_restore_state` | Restore state from disk (legacy) |
 
+### Certificate Management
+| Tool | Description |
+|------|-------------|
+| `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 acme.sh + Cloudflare DNS |
+| `haproxy_renew_cert` | Renew specific certificate (force option available) |
+| `haproxy_renew_all_certs` | Renew all certificates due for renewal |
+| `haproxy_delete_cert` | Delete certificate from acme.sh and HAProxy |
+
 ## Key Conventions
 
 ### Pool-Based Routing
@@ -359,12 +369,13 @@ echo "set server pool_1/pool_1_1 state ready" | nc localhost 9999
 │   ├── haproxy_client.py # HAProxy Runtime API client
 │   ├── file_ops.py      # File I/O operations
 │   ├── utils.py         # Parsing utilities
-│   └── tools/           # MCP tools (22 total)
+│   └── tools/           # MCP tools (28 total)
 │       ├── domains.py   # Domain management (3 tools)
 │       ├── servers.py   # Server management (7 tools)
 │       ├── health.py    # Health checks (3 tools)
 │       ├── monitoring.py # Monitoring (4 tools)
-│       └── configuration.py # Config management (4 tools)
+│       ├── configuration.py # Config management (4 tools)
+│       └── certificates.py # Certificate management (6 tools)
 ├── conf/
 │   ├── haproxy.cfg      # Main HAProxy config (100 pool backends)
 │   ├── domains.map      # Domain → Pool mapping