Implement the 023-clear-encounter feature that adds a clear encounter button with confirmation dialog to remove all combatants and reset round/turn counters, with the cleared state persisting across page refreshes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/application/src/clear-encounter-use-case.ts

@@ -0,0 +1,21 @@
+import {
+	clearEncounter,
+	type DomainError,
+	type DomainEvent,
+	isDomainError,
+} from "@initiative/domain";
+import type { EncounterStore } from "./ports.js";
+
+export function clearEncounterUseCase(
+	store: EncounterStore,
+): DomainEvent[] | DomainError {
+	const encounter = store.get();
+	const result = clearEncounter(encounter);
+
+	if (isDomainError(result)) {
+		return result;
+	}
+
+	store.save(result.encounter);
+	return result.events;
+}