Different blocking for different devices: steps and client groups

Client groups put devices (addresses, networks, or ACLs of them) at a
blocking step: off (only your rules), normal (the default), or steps
added above it, each including the lists of the steps below. Lists
start at a step. In each view, a gate policy zone in front of a step's
lists lets the devices below that step through (rpz-client-ip triggers
with rpz-passthru), so every list is still loaded once. The IPv6 part
of a gate leaves the IPv4-mapped range out: named matches IPv4 clients
as ::ffff:a.b.c.d.

Web UI: a Devices panel on the Blocking page and a step on each list.
CLI: jarl block step, jarl block group, jarl blocklist --step. API:
/blocking/steps, /blocking/groups. Database schema 8.

Also: copying the state kept empty lists as empty (not nil), so
reverting a changeset no longer adds restore operations for unchanged
blocklists, rules and views.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/engine/ops.go

@@ -106,6 +106,14 @@ func applyOp(st *model.State, op model.Op, c *applyCtx) error {
 		err = applyBlockRulePut(st, op, c)
 	case OpBlockRuleDelete:
 		err = applyBlockRuleDelete(st, op, c)
+	case OpBlockStepCreate, OpBlockStepUpdate:
+		err = applyBlockStepPut(st, op, c)
+	case OpBlockStepDelete:
+		err = applyBlockStepDelete(st, op, c)
+	case OpClientGroupCreate, OpClientGroupUpdate:
+		err = applyClientGroupPut(st, op, c)
+	case OpClientGroupDelete:
+		err = applyClientGroupDelete(st, op, c)
 	case OpBlockingPause:
 		err = applyBlockingPause(st, op, c)
 	default: