refactor(web): 前端目录重构 — consoles/pages → layouts/features + shared

- consoles/admin/ → layouts/admin-layout/
- consoles/workbench/ → layouts/workbench-layout/ + features/chat/
- pages/ → features/ (dashboard, models, projects, not-found)
- components/ → shared/components/
- hooks/ → shared/hooks/
- utils/ → shared/utils/
- 更新所有 import 路径 (src/web/ + tests/web/)
- 更新开发文档 (README.md, frontend.md, architecture.md)

src/web/shared/utils/time.ts

@@ -0,0 +1,46 @@
+export function formatCountdown(seconds: number): string {
+  if (seconds < 60) return `${seconds}秒`;
+  return `${Math.floor(seconds / 60)}分${seconds % 60}秒`;
+}
+
+export function formatDurationUnit(ms: null | number): { suffix: string; value: number } {
+  if (ms === null) return { suffix: "", value: 0 };
+  if (ms < 60000) return { suffix: "秒", value: roundToOne(ms / 1000) };
+  if (ms < 3600000) return { suffix: "分钟", value: roundToOne(ms / 60000) };
+  return { suffix: "小时", value: roundToOne(ms / 3600000) };
+}
+
+export function formatRelativeTime(timestamp: null | string, now = new Date()): string {
+  if (!timestamp) return "尚无检查数据";
+
+  const time = new Date(timestamp).getTime();
+  if (Number.isNaN(time)) return "尚无检查数据";
+
+  const diffSeconds = Math.max(0, Math.floor((now.getTime() - time) / 1000));
+  if (diffSeconds < 60) return `${diffSeconds}秒前`;
+
+  const diffMinutes = Math.floor(diffSeconds / 60);
+  if (diffMinutes < 60) return `${diffMinutes}分钟前`;
+
+  const diffHours = Math.floor(diffMinutes / 60);
+  if (diffHours < 24) return `${diffHours}小时前`;
+
+  return `${Math.floor(diffHours / 24)}天前`;
+}
+
+export function isOlderThan(timestamp: null | string, ageMs: number, now = new Date()): boolean {
+  if (!timestamp) return false;
+  const time = new Date(timestamp).getTime();
+  if (Number.isNaN(time)) return false;
+  return now.getTime() - time > ageMs;
+}
+
+export function subtractHours(date: Date, hours: number): Date {
+  const result = new Date(date);
+  result.setTime(result.getTime() - hours * 60 * 60 * 1000);
+  return result;
+}
+
+function roundToOne(value: number): number {
+  return Math.round(value * 10) / 10;
+}