Add video download failure reporting feature

- Introduced a new API endpoint `POST /api/v1/video/remove_watermark/report_failure` for reporting download failures.
- Added a new database table `video_download_failures` to store details about failed downloads, including domain, URL, error message, and reporting metadata.
- Updated the video handler to process failure reports and save them to the database.
- Enhanced documentation to include details about the new reporting feature and its usage.

cmd/api/main.go

@@ -45,6 +45,7 @@ func main() {
 		&membershipmodel.MembershipRedemption{},
 		&rmmodel.VideoParseLog{},
 		&rmmodel.VideoParseUnlock{},
+		&rmmodel.VideoDownloadFailure{},
 		&smokemodel.SmokeLog{},
 		&smokemodel.SmokeAIAdvice{},
 		&smokemodel.SmokeAIAdviceUnlock{},