Add the convention hub landing screen: a pure schedule engine
(analyzeSchedule) classifies each slot as live/next/done/upcoming from an
injected now; <con-hub> renders the slate + summary and emits open-scenario;
a scenario registry resolves a slot's scenarioId to its module; gm-shell
routes hub<->session (hiding/restoring the Rail) with a home rail chip.
Ships continuum-2026.js with the real slate (only AFTERIMAGE ported;
others scenarioId:null, start-times TBC) and a fully-timed example-con.js
template/fixture. 122 tests pass; build clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
