- Set data-theme=dark as default in index.html, useTheme defaults to 'dark' (issues 1, 10)
- Rename "Cron" to "Cron 管理" in sidebar (issue 2)
- Set card grid gap to 14px per design spec (issue 3)
- Show D-grade profile names below health bar chart (issue 4)
- Remove R/F/H/OK text from timeline, use colored dots with hover tooltip (issue 5)
- Wire live online/running/offline counts via usePolling in header, add offline badge (issue 9)
- Fix search placeholder to "搜索 Profile / 任务 / Cron / 事件..." (issue 9)
Co-Authored-By: Claude <noreply@anthropic.com>
