Improved detection of the node to resize. btrtile now handles client resizing based on the nearest client edge in the resize direction. It also handles resizing of clientless split nodes, making the behavior feel more intuitive.
- **Mouse-based Client Selection:**
- If no visible client is found under the cursor, fallback to selecting the closest client.
- **Client Insertion:**
- Handle insertion of multiple new clients.
- When moving multiple clients to another tag, ensure the splitting logic is consistently applied.