* feat(en): add file-preview API to OpenAPI specifications
- Add GET /files/{file_id}/preview endpoint to chat, chatflow, and workflow APIs
- Support file preview and download with as_attachment parameter
- Include proper error handling (400, 403, 404, 500)
- Update Files tag descriptions to include preview operations
- Maintain unique operationIds for each API type
- Align with existing API patterns and template specifications
Resolves: #389
* feat(ja-jp): add file-preview API to Japanese OpenAPI specifications
- Add GET /files/{file_id}/preview endpoint to chat, chatflow, and workflow APIs
- Use Japanese descriptions and maintain "Ja"/"Jp" operationId suffixes
- Support file preview and download with as_attachment parameter
- Include proper error handling with Japanese error messages
- Update Files tag descriptions to include preview operations
- Maintain consistency with existing Japanese API patterns
Related: #389
* feat(zh-hans): add file-preview API to Chinese OpenAPI specifications
- Add GET /files/{file_id}/preview endpoint to chat, chatflow, and workflow APIs
- Use Chinese descriptions and maintain "Cn" operationId suffixes
- Support file preview and download with as_attachment parameter
- Include proper error handling with Chinese error messages
- Update Files tag descriptions to include preview operations
- Maintain consistency with existing Chinese API patterns
Related: #389