# Management Change Certificate Empty State Review

## Summary

Updated certificate preview fallback states in training records so the UI never shows a broken image, empty cell, or `-` for missing attachments. The table and certificate manager now use a shared placeholder style with the same certificate icon treatment.

## Changes

- Added shared empty-state support to `CertificatePlaceholder`
- Updated training record table preview to show:
  - image preview when previewable image exists
  - certificate placeholder with file type for non-previewable or broken previews
  - certificate placeholder with `ไม่มีไฟล์แนบ` when no file exists
- Updated certificate manager empty state to use the same placeholder card instead of plain text

## Files

- `src/features/training-records/components/certificate-preview-utils.tsx`
- `src/features/training-records/components/training-record-tables/training-record-image-preview.tsx`
- `src/features/training-records/components/training-record-certificate-manager.tsx`

## Behavior

Case 1: Previewable image exists

- shows image preview

Case 2: File exists but is not previewable, or image preview fails

- shows certificate icon
- shows `เกียรติบัตร`
- shows file type such as `PDF`, `DOC`, `XLS`, `ZIP`

Case 3: No file attached

- shows certificate icon
- shows `ไม่มีไฟล์แนบ`

## Manual Test Checklist

- [ ] Image certificate displays preview.
- [ ] PDF certificate shows certificate icon and PDF.
- [ ] DOCX certificate shows certificate icon and DOCX.
- [ ] Broken image shows certificate icon.
- [ ] No attachment shows certificate icon and `ไม่มีไฟล์แนบ`.
- [ ] No table cell displays `-`.
- [ ] Download/open still works when file exists.
- [ ] Mobile/table layout does not break.
