feat: Implement direct upload functionality for desktop client releases

- Added new endpoints for initiating and completing direct uploads of desktop client packages.
- Introduced request and response structures for direct upload operations.
- Enhanced the upload process to support SHA256 and Content-MD5 validation.
- Updated the frontend to reflect changes in upload button states and progress indicators.
- Modified object storage clients to support presigned PUT URLs with content type and MD5 headers.
- Added tests for direct upload functionality and ensured existing upload processes remain intact.

server/internal/ops/transport/router.go

@@ -173,6 +173,8 @@ func RegisterRoutes(d Deps) {
 
 		authed.GET("/desktop-client/releases", listDesktopClientReleasesHandler(d.Releases))
 		authed.POST("/desktop-client/releases/upload", uploadDesktopClientReleaseHandler(d.Releases))
+		authed.POST("/desktop-client/releases/direct-upload", initiateDesktopClientReleaseDirectUploadHandler(d.Releases))
+		authed.POST("/desktop-client/releases/direct-upload/complete", completeDesktopClientReleaseDirectUploadHandler(d.Releases))
 		authed.POST("/desktop-client/release-uploads", initiateDesktopClientReleaseUploadHandler(d.Releases))
 		authed.POST("/desktop-client/release-uploads/:upload_id/chunks/:chunk_index", uploadDesktopClientReleaseChunkHandler(d.Releases))
 		authed.POST("/desktop-client/release-uploads/:upload_id/complete", completeDesktopClientReleaseUploadHandler(d.Releases))