Slack: upgrade streamed markdown tables to native blocks

[mohankumarelec]

What changed

• upgrades streamed markdown tables into native Slack table blocks once stream is done
• keeps stopBlocks when doing that final chat.update
• adds tests for table + no-table stream paths and postMessage behavior

Validation

• pnpm check
• pnpm test --filter=@chat-adapter/slack...

Small behavior fix, should be safer for current bots too.

[vercel]

@mohankumarelec is attempting to deploy a commit to the Vercel Labs Team on Vercel.

A member of the Team first needs to authorize it.

[cramforce]

I'm not sure this is desirable. It's a tough one

[mohankumarelec]

@cramforce , since slack now supports native markdown table, it has few extra features like rendering large tables in an expanded window, exporting the table in tsv and so on.

Do you see downsides of implementing this ?

[cramforce]

The main downside is that the shape of the rendering ends at the very end of the stream. So, if you are actually following along you have a janky experience.

In fact, we originally did this and it was often jarring. If we knew that nobody was watching, it would definitely be better to use native rendering.

[mohankumarelec]

@cramforce , got it , makes sense