* Avoid showing system message content in history
* Bug in schema (wrong video_content dependency)
* Add/replace video-embeds
* Rephrase odelia to avoid "compulsory color schtick"

Also:

* Do not crash when session has no history
* Tv-frame style for embeds

Also display flash messages if needed

`prompt.txt` template also contains (via jinja)

* chat.schema.json
* chat-example.json
* in the future, there will be patient-specific variants