Fix ARG_MAX overflow: use filter_complex_script instead of -vf

- trace_video filter string can exceed macOS 256KB limit
- Write filter to temp file, pass with -filter_complex_script

src/api/media_api.rs

@@ -330,15 +330,21 @@ async fn trace_video(
 
     let tmp = std::env::temp_dir().join(format!("trace_{}.mp4", uuid::Uuid::new_v4()));
     let tmp_str = tmp.to_str().unwrap_or("").to_string();
+    // Write filter to temp file to avoid ARG_MAX overflow
+    let filter_file = std::env::temp_dir().join(format!("vf_{}.txt", uuid::Uuid::new_v4()));
+    let filter_path = filter_file.to_str().unwrap_or("");
+    let _ = std::fs::write(&filter_file, &vf);
     let status = std::process::Command::new("ffmpeg")
         .args([
             "-ss", &seek.to_string(), "-i", &video_path,
-            "-t", &duration.to_string(), "-vf", &vf,
+            "-t", &duration.to_string(),
+            "-filter_complex_script", &filter_path,
             "-c:v", "libx264", "-preset", "ultrafast", "-crf", "28",
             "-an", "-movflags", "+faststart", "-y", &tmp_str,
         ])
         .status()
         .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+    let _ = std::fs::remove_file(&filter_file);
     if !status.success() {
         let _ = std::fs::remove_file(&tmp);
         return Err(StatusCode::INTERNAL_SERVER_ERROR);