feat: 智能体与技能列表显示创建时间字段

- 新增共享 formatDateTime 工具(YYYY-MM-DD HH:mm)
- agent-card 卡片/列表视图在发布者下方显示创建时间
- skill 设置页 metaNodes 显示创建时间

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend-web/src/components/workspace/agents/agent-card.tsx

@@ -2,6 +2,7 @@
 
 import {
   BotIcon,
+  ClockIcon,
   CopyIcon,
   EyeOffIcon,
   GlobeIcon,
@@ -78,6 +79,7 @@ import type { Agent, AgentQuestion, UpdateAgentRequest } from "@/core/agents";
 import { getStoredAuth } from "@/core/auth";
 import { useI18n } from "@/core/i18n/hooks";
 import { useSkills } from "@/core/skills/hooks";
+import { formatDateTime } from "@/core/utils/datetime";
 import { desensitize } from "@/lib/desensitize";
 import { cn } from "@/lib/utils";
 
@@ -605,6 +607,17 @@ export function AgentCard({ agent, layout = "card", onPublisherClick }: AgentCar
       </button>
     ) : null;
 
+  const createdAtText = formatDateTime(agent.created_at);
+  const createdAtNode = createdAtText ? (
+    <div
+      className="text-muted-foreground flex max-w-full items-center gap-1 text-xs"
+      title={`创建时间：${createdAtText}`}
+    >
+      <ClockIcon className="size-3.5 shrink-0" />
+      <span className="truncate">创建时间：{createdAtText}</span>
+    </div>
+  ) : null;
+
   // 技能英文名 → 中文名映射,用于把智能体的技能徽章显示为中文(agent.skills 只存英文名)。
   const skillNameZhMap = useMemo(() => {
     const map = new Map<string, string>();
@@ -820,6 +833,7 @@ export function AgentCard({ agent, layout = "card", onPublisherClick }: AgentCar
           </CardDescription>
         )}
         {publisherNode && <div className="mt-2">{publisherNode}</div>}
+        {createdAtNode && <div className="mt-1">{createdAtNode}</div>}
       </CardHeader>
 
       {(agent.tags?.length ?? 0) > 0 && (
@@ -866,6 +880,7 @@ export function AgentCard({ agent, layout = "card", onPublisherClick }: AgentCar
           </p>
         )}
         {publisherNode && <div className="mt-0.5">{publisherNode}</div>}
+        {createdAtNode && <div className="mt-0.5">{createdAtNode}</div>}
       </div>
       <div className="flex shrink-0 items-center gap-1">
         {showActionRow && actionButtons}

frontend-web/src/components/workspace/settings/skill-settings-page.tsx

@@ -86,6 +86,7 @@ import {
 } from "@/core/skills/hooks";
 import { usePublishSquares, useViewMode } from "@/core/system-settings/hooks";
 import type { Skill } from "@/core/skills/type";
+import { formatDateTime } from "@/core/utils/datetime";
 import { env } from "@/env";
 import { desensitize } from "@/lib/desensitize";
 import { cn } from "@/lib/utils";
@@ -848,6 +849,14 @@ export function SkillRow({
             : t.settings.skills.useCountInlineZero}
         </div>
       )}
+      {formatDateTime(skill.created_at) && (
+        <div className="text-muted-foreground mt-1 flex items-center gap-1 text-xs">
+          <ClockIcon className="size-3.5 shrink-0" />
+          <span className="truncate">
+            创建时间：{formatDateTime(skill.created_at)}
+          </span>
+        </div>
+      )}
       {(skill.tags?.length ?? 0) > 0 && (
         <TagChipList tags={skill.tags!} className="mt-2" />
       )}

frontend-web/src/core/utils/datetime.ts

@@ -25,3 +25,18 @@ export function formatTimeAgo(date: Date | string | number, locale?: Locale) {
     locale: getDateFnsLocale(effectiveLocale),
   });
 }
+
+/**
+ * Format a created/updated timestamp as `YYYY-MM-DD HH:mm`.
+ * Returns an empty string for missing or unparseable values.
+ */
+export function formatDateTime(value?: Date | string | number | null): string {
+  if (value === null || value === undefined || value === "") return "";
+  const date = value instanceof Date ? value : new Date(value);
+  if (Number.isNaN(date.getTime())) return "";
+  const pad = (n: number) => String(n).padStart(2, "0");
+  return (
+    `${date.getFullYear()}-${pad(date.getMonth() + 1)}-${pad(date.getDate())} ` +
+    `${pad(date.getHours())}:${pad(date.getMinutes())}`
+  );
+}