only allow messages from verified sessions

**Is your feature request related to a problem? Please describe.**
blocked by e2e

**Describe the solution you'd like**
only allow the bot to be accessed by users from verified sessions so if a user is comprimised they still can't access the bot

**Describe alternatives you've considered**
maybe a password to run commands but i can't think of a way to do that that isn't horrible to use

**Additional context**
this would allow a room to be fully moderated by a moderation team with only one account having admin in the room, reducing the attack surface

The issue names no files, tests, or entry points; start by locating how bot access and user sessions are currently verified, then read the end-to-end tests mentioned as a blocker. Done means access to the bot is restricted to users with verified sessions, while remaining usable for the proposed moderation-team workflow.

Written by the indexing model from the issue text.