Redirect /hls/stream.m3u8 to IPFS playlist when available

When the local HLS playlist doesn't exist, check for IPFS playlist
CID in pending/completed run and redirect to the IPFS gateway.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/routers/runs.py

@@ -1079,6 +1079,26 @@ async def serve_hls_content(
     else:
         raise HTTPException(400, "Invalid file type")
 
+    # For playlist requests, check IPFS first (redirect to IPFS gateway)
+    if filename == "stream.m3u8" and not file_path.exists():
+        import database
+        from fastapi.responses import RedirectResponse
+        await database.init_db()
+
+        # Check pending run for IPFS playlist
+        pending = await database.get_pending_run(run_id)
+        if pending and pending.get("ipfs_playlist_cid"):
+            gateway = os.environ.get("IPFS_GATEWAY_URL", "https://ipfs.io/ipfs")
+            ipfs_url = f"{gateway}/{pending['ipfs_playlist_cid']}"
+            return RedirectResponse(url=ipfs_url, status_code=302)
+
+        # Check completed run cache
+        run = await database.get_run_cache(run_id)
+        if run and run.get("ipfs_playlist_cid"):
+            gateway = os.environ.get("IPFS_GATEWAY_URL", "https://ipfs.io/ipfs")
+            ipfs_url = f"{gateway}/{run['ipfs_playlist_cid']}"
+            return RedirectResponse(url=ipfs_url, status_code=302)
+
     # Try local file first
     if file_path.exists():
         return FileResponse(