Customizable Message Syncing for Dex Copilot

Request to enhance message syncing by allowing users to define a custom timeframe (e.g., sync messages from the last 30 days) and exclude specific contacts from sync or Copilot visibility. This would improve the utility of Dex Copilot for tasks like summarizing recent conversations or generating follow-up questions.

The ability to selectively backfill messages and manage visibility settings would provide users with more control over their data and tailor Copilot behavior to individual workflows.