Add private Composio alias setup checklist

[AojdevStudio]

What to build

Add setup guidance for the configuration agent that connects accounts in Composio and stores the concrete alias inventory in private agent memory/config. The repo should document the process and constraints, not the user's actual mailbox list.

Acceptance criteria

• The guide instructs the configuration agent to connect each mailbox through Composio.
• The guide instructs the configuration agent to assign owner-scoped mailbox aliases during setup.
• The guide instructs the configuration agent to store the concrete alias inventory outside the repo in private memory/config.
• The guide explicitly says not to commit raw email addresses or private mailbox inventories.
• The guide includes a verification step that aliases can select the intended Composio connected accounts.

Blocked by

• Document Composio as a companion MCP path #80
• Define Composio connected-mailbox terminology #81

[linear]

GDRIVE-35