Add unit tests for PDF Packager converter functionality

- Implement tests for converter properties, ensuring correct input and output formats.
- Add tests for chip parsing, covering various image, pdf_image, and pdfa chip formats.
- Include tests for the isArchiveOutput and getOutputFileName functions.
- Mock execFile for testing the convert function, verifying command execution and output file creation.
- Ensure all chips are parseable and validate the completeness of chip categories.

docs/環境變數總覽.md

@@ -150,6 +150,37 @@ environment:
 
 ---
 
+## 📝 PDF Packager 設定
+
+### PDF 數位簽章
+
+PDF Packager 預設**開箱即用**，Docker 建置時已自動產生預設憑證。如需使用自訂憑證，可透過以下環境變數配置：
+
+| 變數                    | 預設值                     | 說明                |
+| ----------------------- | -------------------------- | ------------------- |
+| `PDF_SIGN_P12_PATH`     | `/app/certs/default.p12`   | PKCS12 憑證檔案路徑 |
+| `PDF_SIGN_P12_PASSWORD` | （空）                     | 憑證密碼            |
+| `PDF_SIGN_REASON`       | `ConvertX-CN PDF Packager` | 簽章原因            |
+| `PDF_SIGN_LOCATION`     | `Taiwan`                   | 簽章地點            |
+| `PDF_SIGN_CONTACT`      | `convertx-cn@localhost`    | 聯絡資訊            |
+
+**使用自訂憑證範例**：
+
+```yaml
+environment:
+  - PDF_SIGN_P12_PATH=/app/certs/company.p12
+  - PDF_SIGN_P12_PASSWORD=your_password
+  - PDF_SIGN_REASON=文件已核准
+  - PDF_SIGN_LOCATION=台北
+  - PDF_SIGN_CONTACT=admin@company.com
+volumes:
+  - /path/to/certs:/app/certs:ro
+```
+
+詳細說明請參考 [PDF Packager 說明](功能說明/PDF-Packager.md)。
+
+---
+
 ## 相關文件
 
 - [Docker 部署指南](部署指南/Docker部署.md)