Normalise IP addresses across backend

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/app/services/jail_service.py

@@ -48,6 +48,7 @@ from app.utils.fail2ban_response import (
     ok,
     to_dict,
 )
+from app.utils.ip_utils import normalise_ip
 from app.utils.jail_socket import reload_all
 from app.utils.runtime_state import JailServiceState  # noqa: TC001
 
@@ -639,6 +640,7 @@ def _parse_ban_entry(entry: str, jail: str) -> DomainActiveBan | None:
 
         # Validate IP
         ipaddress.ip_address(ip)
+        ip = normalise_ip(ip)
 
         if len(parts) < 2:
             # Entry has no time info — return with unknown times.
@@ -1009,6 +1011,7 @@ async def lookup_ip(
     except ValueError as exc:
         raise ValueError(f"Invalid IP address: {ip!r}") from exc
 
+    ip = normalise_ip(ip)
     client = Fail2BanClient(socket_path=socket_path, timeout=FAIL2BAN_SOCKET_TIMEOUT)
 
     with contextlib.suppress(ValueError, Fail2BanConnectionError):