Replaces the generic SimNode/gossip/dashboard framework with a virtual-time
discrete-event engine (priority queue ordered by time/node/fiber/seq), a TOML spec
parser, bundle writer, replay, divergence detector, lint, and postproc, plus the
parity-bar test harness with fixtures and xtask parity-lock tooling. Rewrites
transport identity/crypto and adds the SPEC/TESTING_SPEC/OBSERVABILITY/NORTH_STAR docs.
Signed-off-by: Zachery Aaron Shores-Chmielewski <zacheryasc@gmail.com>