Generate OG summaries for shared chats

[tarasglek]

We should make a cloudflare function that injects OpenGraph title/summary into index.html for shared chats.

Title is title of shared chat and summary should be last message..or if the last message is short last n messages that fit into some string length

[tarasglek]

we might be able to just do this at share time by slightly changing format of shared chat to look like html with OG

[humphd]

I'm adding the ability to screenshot an element in #402, partially with this in mind. Why don't we take a screenshot and POST that to R2 as well?

[tarasglek]

I'm adding the ability to screenshot an element in #402, partially with this in mind. Why don't we take a screenshot and POST that to R2 as well?

Lets do it! This will solve the remaining OG problem of it rendering ugly on sites that prefer image-heavy content