feat: clean error favorites and history

[josexy]

What changed

• add “Clean errors” actions to Favorites and History in the requested toolbar locations
• show a confirmation dialog before cleanup
• refresh saved server snapshots before selecting records for deletion
• delete only records whose fresh snapshot still contains lastQueryError
• abort deletion when the batch refresh fails
• add Chinese and English UI copy and running/result states

Why

Stored server status can become stale. Refreshing immediately before cleanup prevents accidentally deleting records that have recovered since the previous query.

User impact

Favorites cleanup is limited to the currently selected group. History cleanup removes all history records associated with servers that still report an error after the fresh query.

Validation

• npm run build
• cargo test --manifest-path src-tauri/Cargo.toml (130 tests passed)
• git diff --check
• Tauri development app startup smoke test