After a successful swarm boot, fill seedCapabilityInfo with stock
kernelCapabilityWords when the pre-MBR capabilities RPC was skipped,
failed, or lacked words, so peer system seed eligibility passes and
localRAM can serve block 0. Add BARE_OS_PEER_SEED_SYNTHETIC_CAPABILITIES
(opt-out) and BARE_OS_PEER_SEED_ADVERTISE_IMAGE_TIP_ID; document tip
propagation in env appendix, users manual, and handbook. Extend peer
seed tests.
Raven Scott