Function dispatch_host_call_bridge 

pub fn dispatch_host_call_bridge(
    capability: &str,
    operation: &str,
    params: &BTreeMap<String, VmValue>,
) -> Option<Result<VmValue, VmError>>

Dispatch (capability, operation, params) to the currently-installed HostCallBridge, if any. Some(Ok(_)) means the bridge handled the call; Some(Err(_)) means it tried but raised; None means there is no bridge or the bridge declined this op (returned Ok(None)).

Mirrors the inner block of dispatch_host_operation but without the mock-call check or the built-in fallbacks — useful for callers that want to treat the bridge as one of several sinks (e.g. inbound MCP elicitation/create requests).