v0.5.2: offline report + tab UI + persist race fix

- New: Offline earnings report dialog (welcome back popup with gain/duration/rate/progress)
  - src/lib/game/offlineReport.ts: module-level store + custom event
  - src/components/game/OfflineReportDialog.tsx: Radix Dialog UI
  - gameStore.init: setPendingOfflineReport before set()
- Fix: useGameLoop waits for persist.hasHydrated() before init
  - Root cause: Zustand persist rehydrate is async (Promise.resolve wrapper)
  - Before fix: init read INITIAL_STATE (lastTick=undefined), skipped offline branch
  - After fix: init waits for rehydrate, correctly reads saved lastTick
- UI: Tab bar redesign with per-tab accent colors + flex-col layout
- Version: v0.5 -> v0.5.2

src/lib/game/offlineReport.ts

@@ -0,0 +1,46 @@
+// 回响星核 / Echo Nexus — 离线收益报告（v0.5.2）
+// 模块级存储 + 自定义事件通知 UI，不污染 GameState
+
+export interface OfflineReport {
+  elapsedSec: number; // 离线秒数（已 cap）
+  rawElapsedSec: number; // 实际离线秒数（未 cap）
+  gain: number; // 获得晶体
+  rate: number; // 离线时产能 /s
+  eff: number; // 离线效率 0-1
+  capped: boolean; // 是否触达 8h 上限
+  crystalsBefore: number; // 补发前晶体
+  crystalsAfter: number; // 补发后晶体
+  crystalCap: number; // 仓库上限
+}
+
+let pending: OfflineReport | null = null;
+
+export function setPendingOfflineReport(r: OfflineReport) {
+  pending = r;
+  if (typeof window !== "undefined") {
+    window.dispatchEvent(new CustomEvent("echo-nexus-offline-report"));
+  }
+}
+
+export function getPendingOfflineReport(): OfflineReport | null {
+  return pending;
+}
+
+export function consumeOfflineReport(): OfflineReport | null {
+  const r = pending;
+  pending = null;
+  return r;
+}
+
+/** 格式化时长为中文 */
+export function formatDuration(sec: number): string {
+  if (sec < 60) return `${Math.floor(sec)}秒`;
+  const m = Math.floor(sec / 60);
+  if (m < 60) return `${m}分钟`;
+  const h = Math.floor(m / 60);
+  const remM = m % 60;
+  if (h < 24) return remM > 0 ? `${h}小时${remM}分` : `${h}小时`;
+  const d = Math.floor(h / 24);
+  const remH = h % 24;
+  return remH > 0 ? `${d}天${remH}小时` : `${d}天`;
+}