Fix blocklist-import bantime, unify filter bar, and improve config navigation

backend/app/services/config_service.py

@@ -368,8 +368,9 @@ async def update_jail_config(
         await _set("datepattern", update.date_pattern)
     if update.dns_mode is not None:
         await _set("usedns", update.dns_mode)
-    if update.backend is not None:
-        await _set("backend", update.backend)
+    # Fail2ban does not support changing the log monitoring backend at runtime.
+    # The configuration value is retained for read/display purposes but must not
+    # be applied via the socket API.
     if update.log_encoding is not None:
         await _set("logencoding", update.log_encoding)
     if update.prefregex is not None: