fix(channels): the Length column shows the sum alone

The "+N without length" line did not fit the 4.5 rem column (88 px of
text in a 56 px cell) and spilled into Tags. The owner wants no such
line there: the cell shows the summed hours, and the channel list no
longer sends a count nothing reads. A playlist's total keeps it.

backend/app/routes/channels.py

@@ -46,12 +46,11 @@ def list_channels(user: User = Depends(current_user), db: Session = Depends(get_
     # computed here — the manager table dropped its N/S/L column.)
     channel_ids = [c.id for _, c in rows]
     agg: dict[str, dict] = {}
-    for cid, n, last_up, total_dur, live in queries.aggregates(db, channel_ids):
+    for cid, n, last_up, total_dur in queries.aggregates(db, channel_ids):
         agg[cid] = {
             "stored": n,
             "last_video_at": iso(last_up),
             "total_duration_seconds": int(total_dur or 0),
-            "live_without_length": live,
         }
 
     # Channels already in the *global* deep-backfill queue — i.e. at least one user (any
@@ -69,7 +68,6 @@ def list_channels(user: User = Depends(current_user), db: Session = Depends(get_
             "stored_videos": (agg.get(ch.id) or {}).get("stored", 0),
             "last_video_at": (agg.get(ch.id) or {}).get("last_video_at"),
             "total_duration_seconds": (agg.get(ch.id) or {}).get("total_duration_seconds", 0),
-            "live_without_length": (agg.get(ch.id) or {}).get("live_without_length", 0),
             "priority": sub.priority,
             "hidden": sub.hidden,
             "deep_requested": sub.deep_requested,