Single portable 'where we are / what's next' page for the Zig native-substrate
work: gate status per component, the locked G1 CRDT contract, the immediate
next action (a new ADR to clear G2 before any Zig code), env gotchas
(PYO3_PYTHON=3.12; the public_demo wall-clock lane flake), and verification
commands. Lets any operator/agent resume cold.
Sibling links resolve once #509 (docs/zig/**) lands on main; merge #509 first.
