## Summary
A chat-aware run inspector and a `/playground` UI for testing
`chat.agent` tasks interactively. Builds on #3543's runtime.
## Design
The run inspector grows a new tab that renders the conversation chain
for any `chat.agent`-kind run. It subscribes to the run's session
streams, threads chat parts through a per-message renderer, and uses a
shared markdown + Shiki component for code highlighting (also used by
the test-payload panel).
The playground is a standalone `/playground` route that lets you drive a
deployed chat agent from the dashboard — pick a task, send messages,
watch tool calls render, and see span detail on every turn. The matching
`/agents` list view shows all deployed agents in the project.
Eric Allam
16538f6fdb