fix: localize database refresh dialog strings

[alceops]

Summary

• replace the duplicate hardcoded DatabaseRefreshDialog subtitle with an i18n description key
• replace the hardcoded refresh-button parenthetical with locale-backed text
• add the new keys to en-US, zh-CN, ja-JP, and ko-KR

Closes #18

Verification

• python3 static check confirmed all four locale files include databaseConnectionLostDescription and refreshPageParenthetical
• python3 static check confirmed DatabaseRefreshDialog.tsx no longer contains the hardcoded Database Connection Lost subtitle or (Refresh Page) span text
• git diff --check

Note: this cron VM does not have node/pnpm, so I could not run pnpm -C web run typecheck here.