claude-code: drop what was removed while away, render one at a time, refuse an empty settings set

Review of the nox-mesh plugin: a watch hands over what is there, not what
went, so the view is pruned to the state's keys before it starts; the
watches and the tools render one at a time, as the home's record is read
and written whole; the register answer names how an item is offered.

modules/claude-code/cmd/claude-code/config.go

@@ -223,6 +223,23 @@ func (v *ConfigView) Take(key, op string, item *Item) bool {
 	return v.writeThrough()
 }
 
+// Prune drops what the view holds and the state no longer does: a registration removed while this node
+// was away is never handed over by the watch, which hands over what is there, not what went.
+func (v *ConfigView) Prune(present []string) bool {
+	keep := map[string]bool{}
+	for _, k := range present {
+		keep[k] = true
+	}
+	v.mu.Lock()
+	for k := range v.items {
+		if !keep[k] {
+			delete(v.items, k)
+		}
+	}
+	v.mu.Unlock()
+	return v.writeThrough()
+}
+
 // Items is what applies here, by key.
 func (v *ConfigView) Items() map[string]Item {
 	v.mu.Lock()
@@ -730,8 +747,17 @@ func Register(p Paths, it Item, nodes []string, unregister bool, state ConfigSta
 	}
 	verb := map[bool]string{false: "registered", true: "unregistered"}[unregister]
 	answer := map[string]any{verb: it.Kind + " " + it.Name, "keys": keys}
-	if it.Kind != KindSettings && it.Scope != ScopeHome && !unregister {
-		answer["offered as"] = Plugin + ":" + it.Name
+	if !unregister {
+		switch {
+		case it.Scope == ScopeHome && it.Kind == KindCommand:
+			answer["offered as"] = "/" + it.Name
+		case it.Scope == ScopeHome:
+			answer["offered as"] = it.Name + ", from the home"
+		case it.Kind == KindSkill || it.Kind == KindAgent || it.Kind == KindOutputStyle:
+			answer["offered as"] = Plugin + ":" + it.Name
+		case it.Kind == KindCommand:
+			answer["offered as"] = "/" + Plugin + ":" + it.Name
+		}
 	}
 	if changed {
 		rendered, err := RenderNow(p, write)