fix(dashboard): remove unimplemented 'block' busy_input_mode option

The web UI schema advertised 'block' as a busy_input_mode choice, but
no implementation ever existed — the gateway and CLI both silently
collapsed 'block' (and anything other than 'queue') to 'interrupt'.
Users who picked 'block' in the dashboard got interrupts anyway.

Drop 'block' from the select options. The two supported modes are
'interrupt' (default) and 'queue'.

hermes_cli/web_server.py

@@ -287,7 +287,7 @@ _SCHEMA_OVERRIDES: Dict[str, Dict[str, Any]] = {
     "display.busy_input_mode": {
         "type": "select",
         "description": "Input behavior while agent is running",
-        "options": ["queue", "interrupt", "block"],
+        "options": ["interrupt", "queue"],
     },
     "memory.provider": {
         "type": "select",