Implement the 005-set-initiative feature that adds initiative values to combatants with automatic descending sort and active turn preservation

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

apps/web/src/App.tsx

@@ -14,6 +14,8 @@ function formatEvent(e: ReturnType<typeof useEncounter>["events"][number]) {
 			return `Removed combatant: ${e.name}`;
 		case "CombatantUpdated":
 			return `Renamed combatant: ${e.oldName} → ${e.newName}`;
+		case "InitiativeSet":
+			return `Initiative: ${e.combatantId} ${e.previousValue ?? "unset"} → ${e.newValue ?? "unset"}`;
 	}
 }
 
@@ -77,6 +79,7 @@ export function App() {
 		addCombatant,
 		removeCombatant,
 		editCombatant,
+		setInitiative,
 	} = useEncounter();
 	const activeCombatant = encounter.combatants[encounter.activeIndex];
 	const [nameInput, setNameInput] = useState("");
@@ -107,6 +110,23 @@ export function App() {
 							isActive={i === encounter.activeIndex}
 							onRename={editCombatant}
 						/>{" "}
+						<input
+							type="number"
+							value={c.initiative ?? ""}
+							placeholder="Init"
+							style={{ width: "4em" }}
+							onChange={(e) => {
+								const raw = e.target.value;
+								if (raw === "") {
+									setInitiative(c.id, undefined);
+								} else {
+									const n = Number.parseInt(raw, 10);
+									if (!Number.isNaN(n)) {
+										setInitiative(c.id, n);
+									}
+								}
+							}}
+						/>{" "}
 						<button type="button" onClick={() => removeCombatant(c.id)}>
 							Remove
 						</button>

apps/web/src/hooks/use-encounter.ts

@@ -4,6 +4,7 @@ import {
 	advanceTurnUseCase,
 	editCombatantUseCase,
 	removeCombatantUseCase,
+	setInitiativeUseCase,
 } from "@initiative/application";
 import type { CombatantId, DomainEvent, Encounter } from "@initiative/domain";
 import {
@@ -92,6 +93,19 @@ export function useEncounter() {
 		[makeStore],
 	);
 
+	const setInitiative = useCallback(
+		(id: CombatantId, value: number | undefined) => {
+			const result = setInitiativeUseCase(makeStore(), id, value);
+
+			if (isDomainError(result)) {
+				return;
+			}
+
+			setEvents((prev) => [...prev, ...result]);
+		},
+		[makeStore],
+	);
+
 	return {
 		encounter,
 		events,
@@ -99,5 +113,6 @@ export function useEncounter() {
 		addCombatant,
 		removeCombatant,
 		editCombatant,
+		setInitiative,
 	} as const;
 }