New doc: docs/MULTI-AGENT-HOST-PLAN.md — gap analysis of the multi-host
coordination stack after PR #83 (socat bridge + Python pollers). Defines 5
phases: Phase 1 (multi-agent task-board tests), Phase 2 (merge CLI surface
gaps), Phase 3 (agent presence schema, deferred), Phase 4 (polling workflow
test, deferred), Phase 5 (TCP bridge validation, FreeBSD-only).
Immediate scope: Phases 1-2, all Linux-testable.
Updated PRIORITY-HANDOFF-ISO-SPAWN-COST.md to mark Priorities 2 (poll_tasks)
and 3 (cost mode enforcement) as done, fix stale test count (164 → 211), and
cross-reference the new plan as the next sprint.
211 tests pass, clippy clean, fmt clean.
