feat(treasure): add treasure quest, quest modal, island node, quest widget

src/hooks/useCrewRank.ts

@@ -0,0 +1,13 @@
+import { QUEST_ARCS } from "../data/questData";
+
+// Returns the player's current crew rank, or a default if none earned yet
+export function getCrewRank(arcs = QUEST_ARCS): string {
+  const earned = arcs
+    .flatMap((a) => a.nodes)
+    .filter((n) => n.status === "completed" && n.reward.title)
+    .map((n) => n.reward.title!);
+
+  // Return the last one — questData is ordered by difficulty,
+  // so the last earned title is always the highest rank
+  return earned.at(-1) ?? "Cabin Hand";
+}