feat(swarm): close conformance gaps and enforce spec review loop

[reoring]

What

Add Swarm v1 (agent teams) as a first-class, file-backed coordination substrate (mailbox + tasks), with a JSON-only CLI surface and workflow/TUI integration.

Key User-Facing Changes

• New roboppi swarm CLI (JSON-only stdout):
  • members list
  • message send|broadcast|recv|ack (incl. recv --wait-ms + claim tokens)
  • tasks add|list|claim|complete
  • housekeep (mailbox + task recovery)
• Workflow YAML: top-level swarm: config (members + seed tasks) and injected ROBOPPI_SWARM_* env vars.
• TUI: new Swarm tab + swarm_* ExecEvents (metadata-only; no message bodies/task descriptions).
• Worker capability wiring: MAILBOX / TASKS plumbed through CLI/workflow/daemon layers (Claude Code allowlist maps to restricted roboppi swarm:*).

Implementation Notes

• Maildir-style store: tmp+rename for deliver/claim/ack; deterministic ordering where relevant.
• Crash recovery:
  • mailbox: stale processing/ requeue + bounded retries + dead-letter.
  • tasks: stale in_progress/ requeue to pending/ with atomic metadata rewrite (task_requeued).
• Safety:
  • strict size caps for messages/tasks
  • explicit path-safety validation for tool-facing inputs
  • metadata-only _events.jsonl for audit/observability
• Coordinator:
  • periodic housekeeping
  • tails _events.jsonl into the ExecEvent sink
  • bounded shutdown (request/timeout/abort) + cleanup policy from team.json

Docs

• Design: docs/features/swarm.md
• Conformance spec + checklist: docs/spec/swarm.md

Validation

• CI: make test-all
• Focused coverage:
  • unit: tests/unit/swarm/*
  • AT: tests/at/swarm-cli.test.ts, tests/at/swarm-supervised-custom.test.ts