Revert "generate videos from selected z-axis sequences"

This reverts commit f568faf6ed.

web_backend.py

@@ -865,14 +865,13 @@ class Handler(BaseHTTPRequestHandler):
                 max_angle = float(body.get("maxAngle", 20))
                 duration = float(body.get("durationSeconds", 6))
                 show_arrow = bool(body.get("showArrow", True))
-                source_label = body.get("sourceLabel", "DICOM")
 
                 def worker(job_id):
                     job_root = RESULT_DIR / job_id
                     reset_dir(job_root)
                     output_file = job_root / f"head_extension_{job_id}.mp4"
-                    set_job(job_id, message=f"正在生成 {source_label} 的 z 轴序列视频。")
-                    output = generate_video(input_dir, output_file, max_angle, duration, show_arrow, source_label)
+                    set_job(job_id, message="正在生成 0° 到目标角度的视频。")
+                    output = generate_video(input_dir, output_file, max_angle, duration, show_arrow)
                     output = Path(output).resolve()
                     return {
                         "video": {