Split pearcord-drive/mux-wire into common/v1/v2/gossip modules with unchanged barrel exports. Add dual-stack live smoke, view rpcWireVersion, and doc/CI hardening. No behavior change; default PEARCORD_RPC_WIRE remains v1.
Split pearcord-drive/mux-wire into common/v1/v2/gossip modules with unchanged barrel exports. Add dual-stack live smoke, view rpcWireVersion, and doc/CI hardening. No behavior change; default PEARCORD_RPC_WIRE remains v1.