feat: logo + standardized header across all rSpace pages
- Add logo.png to every rstack-header (landing, canvas, index, admin, create-space, renderShell, module landing)
- Landing page: replace Next.js nav with standard rstack-header (app-switcher, MI bar, identity, Try Demo)
- index.html, admin.html, create-space.html: add RStackMi import + define
- index.html: add auth-change listener for space switcher reload
- shell.css: add .rstack-header__logo style (28px rounded)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Jeff Emmett
c54be8e043