Salvages #26791 by @Niraven. Adds 'hermes kanban swarm' to create a
durable Kanban Swarm v1 graph: a completed root/blackboard card,
parallel worker cards, a verifier gated on all workers, and a
synthesizer gated on the verifier. Stores shared swarm blackboard
updates as structured JSON comments on the root card.
Self-contained: new hermes_cli/kanban_swarm.py module + CLI wiring +
unit tests.
