Use-case page: background agents (task in, PR out)

[stubbi]

Context

Background and async coding agents (fix CVEs, review code, modernize, open PRs without a human laptop) have the strongest enterprise proof in the whole research (publicly reported: Ramp, Stripe at high AI-authored PR volume; E2B markets a Background Agents hero). They need a per-task ephemeral isolated environment plus durable workspaces to resume, and fork to run many tasks at once.

Deliverable

• A page with "a microVM per background task on your own cluster" and a GitHub Action / webhook trigger pattern.
• Link to the background-agent example (task to PR via the git rendezvous output).

Links

• Backed by mitos-run/mitos A3 (background-agent example), relates Brand & website: the path to world-class #21 (git rendezvous).
• Part of the use-cases hub (C1).

Done when

• Page is live with the trigger pattern and example link.