[client] Unify peer and route ACL filtering with multi-source rules (#6322)

* Unify peer and route ACL filtering with multi-source peer rules

* Remove partial userspace firewall mode and open foreign chains via a table-less allower

* Snapshot iptables rule maps before persisting state

* Scope userspace firewall wildcard source rules per address family

* Install nftables peer filter and mangle rules in a single transaction

* Share the iptables jump rule spec between install and cleanup

* Fix legacy ACL source wildcard and keep rollback tracking on delete failure

* Fix CI: recognize multi-value port set lookups in tests and correct PeerIP lint suppression

* Fall back to per-prefix filter rules when ipset is unavailable

* Annotate legacy PeerIP usages in ACL tests and fix import formatting

* Keep firewall rule bookkeeping in step with the kernel on replace and teardown

* Release the routing reference when the route manager shuts down

* Keep set references and rule tracking consistent when a routing rule fails

client/firewall/manager/forward_rule.go

@@ -13,13 +13,13 @@ type ForwardRule struct {
 	TranslatedPort    Port
 }
 
-func (r ForwardRule) ID() string {
+func (r ForwardRule) ID() RuleID {
 	id := fmt.Sprintf("%s;%s;%s;%s",
 		r.Protocol,
 		r.DestinationPort.String(),
 		r.TranslatedAddress.String(),
 		r.TranslatedPort.String())
-	return id
+	return RuleID(id)
 }
 
 func (r ForwardRule) String() string {