Tasks: Build out a solid coder/coder prototyping experience #854

After dogfooding tasks and prototyping a few UIs, I think Tasks can be a valuable tool for prototyping UIs/CLIs even if that code never gets merged. We can use it for features like the Secrets UI.

However, I ran into a few issues during my experience:

• The Tasks UI after kicking off a task is painful... I sit and look at a black screen (or sometimes app timeouts)
• Our system prompt/CLAUDE.md struggled to log in to the deployment to preview with Playwright
  • Telling the agent to look at develop.sh for credentials and log in did the trick
• It often tried to start the dev server on its own
• Many of my prototypes were around tasks, which did not render on the dev server, and I had to manually import the tasks template
• I had to manually add an enterprise license
• I had to manually check in on the prototypes versus getting notifications when it succeeded
• I want to publish my prototypes into a consistent place and then manually deploy PR previews.

I also found a few bugs. The most painful was coder/agentapi#39, which would happen practically every time I revisited the tab. I would have to refresh every 10 mins. Some other agentapi scrolling bugs too that I couldn't reliably reproduce. I think using this UI a lot will help us find bugs before our customers do

The flow I imagine:

• A product manager kicks off a prototyping job, knowing it may take up 10 mins to create the UI
• During that time, the agent takes and reviews screenshots with Playwright to ensure it is working as expected
• They get a notification when its done (slackme for now?)
• They can easily preview it give additional feedback from there