Standardize empty-state copy across panels

[dushaobindoudou]

Background

We have 8+ variants of "no data" copy scattered across the UI (暂无错误 / 暂无日志 / (空) vs （空） full-width vs half-width brackets / etc). Need consistent template + a shared Empty component.

Acceptance

• All empty-state copy follows the same template
• No more mixed full-width （） vs half-width () brackets in Chinese copy
• (Bonus) Create src/components/shared/Empty.tsx and use in 2+ panels

Full brief: https://github.com/dushaobindoudou/ovo/blob/main/docs/GOOD_FIRST_ISSUES.md (issue #2)

⏱ ~1 h · 🏷 ui-consistency