Balance teammate workloads across email and Messenger

A single assignment limit used to apply to both channels, even though most teammates handle email and live chats at very different rates. Now you can set them separately.

• Per-channel limits: Set different assignment limits for email and Messenger to reflect how each channel actually works.
• Workspace defaults: Configure limits at the workspace level, then override for individual teammates where needed.
• Immediate effect: Limits apply to new assignments straight away, so workloads rebalance as conversations come in.