fix: add web_creator client fallback, friendlier YouTube bot error

- Try multiple YouTube player clients for better compatibility
- Show user-friendly error suggesting upload when YouTube blocks download

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/services/download.py

@@ -45,6 +45,8 @@ def _base_opts() -> dict:
         shutil.copy2(COOKIES_FILE, tmp.name)
         tmp.close()
         opts["cookiefile"] = tmp.name
+    # Enable remote EJS challenge solver for YouTube
+    opts["extractor_args"] = {"youtube": {"player_client": ["default", "web_creator"]}}
     return opts
 
 

backend/app/workers/tasks.py

@@ -76,7 +76,15 @@ async def process_job(ctx: dict, job_id: str):
         os.makedirs(job_media_dir, exist_ok=True)
 
         if job.source_type == "youtube":
-            video_info = await download.download_video(job.source_url, job_media_dir)
+            try:
+                video_info = await download.download_video(job.source_url, job_media_dir)
+            except Exception as dl_err:
+                if "Sign in to confirm" in str(dl_err) or "bot" in str(dl_err):
+                    raise ValueError(
+                        "YouTube blocked this download (bot detection). "
+                        "Try uploading the video file directly instead."
+                    )
+                raise
             job.title = video_info.title
             job.duration = video_info.duration
             job.media_path = video_info.video_path