feat(docs): agent-task issue template, labels, and runner protocol (#3021)
Adds the distributed intelligence infrastructure so remote agents
can autonomously execute v0.8.58 milestone issues:
- .github/ISSUE_TEMPLATE/agent-task.yml — GitHub issue form with six
required sections (Goal, Scope, Key files, Acceptance criteria,
Verification, Out of scope). Auto-labels as agent-ready.
- docs/AGENT_RUNNER.md — pick → claim → worktree → exec → verify → PR
loop with safety rules, label semantics, and the issue body format.
Labels agent-ready, agent-in-progress, needs-human already exist
(created during milestone setup).
Hunter Bown
cef3b92964