Add support for `forward_auth`

[bilogic]

Root cause of "no effect": The 113 agent (mcsdodo/caddy-agent) has no forward_auth support at all — its label parser (caddy-agent-watch.py:385) only handles reverse_proxy, tls, transport_, header_, and handle.abort. The caddy.forward_auth labels are silently dropped; the route it pushes is plain reverse_proxy

caddy-multihost-agent/caddy-agent-watch.py

Line 385 in c1d3899

def parse_container_labels(container, labels, host_ip, snippets=None):

Possible to add support?