Add channel filtering to videos view

- Update index route to accept optional channel query parameter
- Show ALL videos (any status) when filtering by specific channel
- Show only completed videos on main dashboard (no filter)
- Allows viewing all videos in a feed via "View Videos" button

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

main.py

@@ -154,12 +154,22 @@ def logout():
 def index():
     """Render the dashboard with all videos sorted by date."""
     try:
+        channel_id = request.args.get("channel")
+
         with get_db_session() as session:
-            # Query videos for current user's channels, sorted by published date (newest first)
-            videos = session.query(VideoEntry).join(Channel).filter(
-                Channel.user_id == current_user.id,
-                VideoEntry.download_status == DownloadStatus.COMPLETED
-            ).order_by(desc(VideoEntry.published_at)).all()
+            # Base query for current user's videos
+            query = session.query(VideoEntry).join(Channel).filter(
+                Channel.user_id == current_user.id
+            )
+
+            # If channel filter is specified, show ALL videos from that channel
+            if channel_id:
+                query = query.filter(Channel.id == int(channel_id))
+            else:
+                # Otherwise, only show completed videos
+                query = query.filter(VideoEntry.download_status == DownloadStatus.COMPLETED)
+
+            videos = query.order_by(desc(VideoEntry.published_at)).all()
 
             return render_template("dashboard.html", videos=videos)
     except Exception as e: