Function parse_gateway_service_entry 

pub fn parse_gateway_service_entry(
    entry: &str,
) -> Option<(String, GatewayServiceTarget)>

Parses a single class=<target> mapping entry.

Splits on the first = (so a label selector’s own = stays in the target). Returns None for an empty class or an unparseable target. Used per-entry so the repeatable --gateway-service CLI flag can carry multi-label selectors (which contain commas) without them being mistaken for entry separators.