phsl / new-api

- Switch Semi UI Timeline to mode="left" in:
  - web/src/components/layout/NoticeModal.jsx
  - web/src/components/dashboard/AnnouncementsPanel.jsx
- Show both relative and absolute time in the `time` prop (e.g. "3 days ago 2025-02-18 10:30")
- Move auxiliary description to the `extra` prop and remove duplicate rendering from content area
- Keep original `extra` data intact; compute and pass:
  - `time`: absolute time (yyyy-MM-dd HH:mm)
  - `relative`: relative time (e.g., "3 days ago")
- Update data assembly to expose `time` and `relative` without overwriting `extra`:
  - web/src/components/dashboard/index.jsx
- No i18n changes; no linter errors introduced

Why: Aligns Timeline layout across the app and clarifies time context by combining relative and absolute timestamps while preserving auxiliary notes via `extra`.