Tasks: Build out a solid coder/coder prototyping experience

After dogfooding tasks and prototyping [a few UIs](https://github.com/coder/coder/branches/all?query=prototype), 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](https://github.com/coder/registry/blob/main/registry/coder-labs/templates/tasks-docker/main.tf)
- 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](https://github.com/coder/coder/branches/all?query=prototype) and then manually deploy [PR previews](https://github.com/coder/coder/blob/main/.github/workflows/pr-deploy.yaml).

I also found a few bugs. The most painful was https://github.com/coder/agentapi/issues/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](https://registry.coder.com/modules/coder/slackme) for now?)
- They can easily preview it give additional feedback from there