Add a thin orchestration layer that drives the existing Orb runtime to
progress issue-scoped work. OrbProjectManager creates/resumes Orb runs,
assembles context packs, projects OrbEvents into durable project events,
detects needs-input and work-complete conditions, forwards follow-up
messages, and runs the Git/Gitea lifecycle on completion.
Port interfaces (OrbAdapter, OrbRunPort, GitLifecyclePort) make the
orchestrator testable with fakes. The real adapters wrap OrbRuntime and
runPostRunGiteaLifecycle without reimplementing Docker, AgentOS, or
OpenCode.
Idempotency: duplicate starts reuse active runs, duplicate completion
returns cached results, cancel is idempotent. Never auto-merges.
88 tests pass (19 orchestration + 12 event-mapping + orb suite), 2 live
tests skipped; lint and type checks clean.
