fix(tiktok): calculate valid upload chunks

lib/video/video-platforms.ts

@@ -267,6 +267,7 @@ async function publishTiktok(upload: typeof videoUploads.$inferSelect) {
 		"SELF_ONLY";
 	const video = await readFile(upload.videoPath);
 	const chunkSize = Math.min(10 * 1024 * 1024, video.byteLength);
+	const totalChunkCount = Math.max(1, Math.floor(video.byteLength / chunkSize));
 	const init = await fetch(
 		"https://open.tiktokapis.com/v2/post/publish/video/init/",
 		{
@@ -291,7 +292,7 @@ async function publishTiktok(upload: typeof videoUploads.$inferSelect) {
 					source: "FILE_UPLOAD",
 					video_size: video.byteLength,
 					chunk_size: chunkSize,
-					total_chunk_count: Math.ceil(video.byteLength / chunkSize),
+					total_chunk_count: totalChunkCount,
 				},
 			}),
 		},
@@ -308,8 +309,12 @@ async function publishTiktok(upload: typeof videoUploads.$inferSelect) {
 	const uploadUrl = initData.data?.upload_url;
 	if (!uploadUrl || !initData.data?.publish_id)
 		throw new Error("TikTok did not return an upload ticket.");
-	for (let start = 0; start < video.byteLength; start += chunkSize) {
-		const end = Math.min(start + chunkSize, video.byteLength) - 1;
+	for (let chunk = 0; chunk < totalChunkCount; chunk += 1) {
+		const start = chunk * chunkSize;
+		const end =
+			chunk === totalChunkCount - 1
+				? video.byteLength - 1
+				: start + chunkSize - 1;
 		const result = await fetch(uploadUrl, {
 			method: "PUT",
 			headers: {