ci: add E2E tests to release workflow

- Add E2E converter tests in Docker container (verify-image job)
  - Inkscape: SVG → PNG
  - Pandoc: Markdown → HTML
  - LibreOffice: TXT → PDF
  - FFmpeg: Audio generation
  - ImageMagick: PNG → JPEG
  - API healthcheck endpoint

- Add cleanup step for verification containers
- Update verification summary to include E2E results
- Install pandoc and imagemagick in run-bun-test workflow for E2E tests

.github/workflows/run-bun-test.yml

@@ -26,6 +26,12 @@ jobs:
         with:
           bun-version: 1.2.2
 
+      # 安裝 E2E 測試所需的轉換工具
+      - name: Install conversion tools for E2E tests
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y pandoc imagemagick
+
       - name: Install dependencies
         run: bun install