Problem: Event Automation invite emails only support one email address, used as both Sender and Reply-To. There's no way to set these separately — unlike Email Communications and manual event emails, which already support independent Sender/Reply-To fields.

Impact: Institutions that send from a no-inbox address (e.g. alumnioffice@connect.trinhall.cam.ac.uk) can't get replies routed to a real inbox (e.g. alumnioffice@trinhall.cam.ac.uk) for automated invites. Replies get lost.

Requested behavior: Add a Reply-To field to Event Automation email configuration, matching what already exists for manual event emails.

Scoping notes: Workflow emails already use the same BulkEmail model that has a reply_to_emails field, and the send pipeline already respects it when set — the gap is only that the Workflow layer never populates it and has no UI field for it.