feat(synology): implement chunked upload for large videos

[simonxander]

Goal

The goal of this change is to provide a more robust upload mechanism for large video files in SynologyDTPService. By switching from a single-stream upload to a chunked upload process, we improve reliability for very large transfers and align with the Synology C2 API's preferred method for handling significant media payloads.

Changes

• Chunked Upload Logic: Refactored createVideo to use a multi-step upload process:
  • uploadVideoChunks: Reads the video stream in 50MB increments and uploads each chunk sequentially to the new /import/item/chunk endpoint.
  • completeVideoUpload: Sends a final request to /import/item/complete with the total chunk count and metadata (title, description, timestamp) to finalize the file.
• API Configuration:
  • Updated C2Api and synology.yaml to include paths for the new chunk and completion endpoints.
• Client Optimization:
  • Updated configureClient to force HTTP/1.1 and increased the default read timeout to 120 seconds to ensure stable long-running connections during chunk transmission.
  • Simplified sendPostRequest by removing the manual timeout override, relying instead on the pre-configured client.
• Memory Efficiency: Reuses a single byte array buffer for chunking to minimize heap allocations during the transfer of large files.
• Others: Move file content to the end of multipart

Testing

• OOM Validation: Updated SynologyDTPServiceOOMTest to verify that a 1GB video is correctly split into multiple chunks and uploaded without exceeding memory limits.
• Functional Tests: Updated SynologyDTPServiceTest to accommodate the new two-step upload flow (Multipart chunks followed by a FormBody completion) and added a specific case shouldSendMultipleChunksForLargeVideo to verify correct indexing.