- Add Sheet UI component for mobile navigation drawer
- SpaceNav: hamburger menu on mobile, horizontal tabs on desktop
- Join page: specific error messages (expired/maxed/invalid), inline success
state with credits info, already-member handling, skeleton loading
- InviteDialog: add expiry hours input, helper text for email field
- InviteList: new component for admin invite management (revoke, copy link)
- Mobile responsiveness sweep across all space pages, proposals, voting
buttons, member list, settings, demo page, and final vote panel
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
