OPNsense MCP fixes: O1,O2,O4,O6 - narrow except, health check, register host, VLAN tools

src/opnsense_mcp/tools/nat.py

@@ -8,7 +8,7 @@ from typing import Any
 from mcp.server.fastmcp import FastMCP
 
 from opnsense_mcp.audit import audit_log
-from opnsense_mcp.client import get_client
+from opnsense_mcp.client import OpnsenseAPIError, get_client
 from opnsense_mcp.config import settings
 from opnsense_mcp.guards import is_dry_run_response, require_writes
 
@@ -17,7 +17,7 @@ def _search_nat(nat_type: str, search_phrase: str, row_count: int) -> str:
     client = get_client()
     try:
         result = client.search_get("firewall", nat_type, "searchRule", search_phrase, row_count)
-    except Exception:
+    except OpnsenseAPIError:
         result = client.search_grid("firewall", nat_type, "searchRule", search_phrase, row_count)
     return json.dumps(result, indent=2, default=str)