feat(web): D 消息编辑/删除前端入口 + 日志聚合前端(Observability后端tail) + 修api-client契约

- D前端: lib/api/messages.ts(patchMessage/deleteMessage,兼容裸DTO与{message}) + MessageActions.tsx(仅user消息; 单击/右键/450ms长按开Miuix玻璃菜单; 编辑弹窗预填+字数→乐观updateMessageById→patchMessage→失败回滚; 删除确认→deleteMessage→removeMessageById; 乐观气泡禁用) + chat.tsx挂载 + Icon加edit/trash/more
- 日志前端: types(AdminLogLine time:string|number) + adminSystem.adminObservabilityLogs + Observability.tsx 后端分级tail(level筛选chip注明'该级及以上'+等宽行HH:mm:ss.SSS·level着色·source·msg+30s刷新) 下半保留WS回显
- Docs/api-client §6a/§4.2 修正: PATCH /messages/{id} 实际返回 {data:<DTO>} 非 {data:{message}}(前端已双向兼容,避免误导Android)
- 前端 build 绿(167 modules); SSR冒烟11 checks
- 遗留: 未实机登录; 菜单absolute理论上边缘可裁切(可改portal)

frontend/web/src/lib/api/adminSystem.ts

@@ -1,4 +1,6 @@
 import type {
+  AdminLogLine,
+  AdminLogQuery,
   AdminNotification,
   AdminNotificationQuery,
   AdminObservabilityMetrics,
@@ -24,6 +26,18 @@ export function adminObservabilityTrace(limit?: number): Promise<AdminTraceSpan[
 export function adminObservabilityAudit(limit?: number): Promise<AuditRecord[]> {
   return request<AuditRecord[]>(`/admin/observability/audit${limitQuery(limit)}`);
 }
+/** GET /api/v1/admin/observability/logs?level=&limit= — the gateway's structured
+ *  log tail, newest first (owner/admin only). An omitted `level` means “all”; the
+ *  backend defaults `limit` to 200 and caps it at 1000. */
+export function adminObservabilityLogs(
+  params: AdminLogQuery = {}
+): Promise<AdminLogLine[]> {
+  const qs = new URLSearchParams();
+  if (params.level) qs.set("level", params.level);
+  if (params.limit !== undefined) qs.set("limit", String(params.limit));
+  const q = qs.toString();
+  return request<AdminLogLine[]>(`/admin/observability/logs${q ? `?${q}` : ""}`);
+}
 
 /** GET /api/v1/admin/backthink — persisted background-think records (newest first). */
 export function adminBackthink(limit?: number): Promise<BackthinkItem[]> {