feat: mobile Spaces nav and list-based project/workspace views

- Combine Projects and Workspaces into a single 'Spaces' grouped mobile
  nav item that opens a bottom-sheet menu.
- Add SpacesBottomSheet component with Projects/Workspaces options.
- Extend MobileListView with optional renderItem prop for rich rows.
- Redesign mobile ProjectsPage rows to show project description and
  repository chips.
- Replace mobile WorkspacesPage list with compact WorkspaceCard grid,
  matching desktop card content.
- Add mobile-list-* CSS and mobile-workspaces-list spacing.

Quality gates: npm run typecheck, npm run lint clean,
npm test -- --run 87 passed.

apps/web/src/pages/ProjectsPage.tsx

@@ -168,8 +168,32 @@ export const ProjectsPage = () => {
 						items={projects.map((p) => ({
 							id: p.id,
 							title: p.name,
-							subtitle: `${p.repositories?.length ?? 0} repo${(p.repositories?.length ?? 0) !== 1 ? "s" : ""}${p.description ? " · " + p.description : ""}`,
 						}))}
+						renderItem={(item) => {
+							const project = projects.find((p) => p.id === item.id);
+							if (!project) return null;
+							return (
+								<div className="mobile-list-item-content mobile-list-item-content-rich">
+									<div className="mobile-list-item-title">{project.name}</div>
+									{project.description && (
+										<p className="mobile-list-item-description">
+											{project.description}
+										</p>
+									)}
+									<div className="mobile-list-item-chips">
+										{(project.repositories?.length ?? 0) === 0 ? (
+											<span className="mobile-list-item-chip muted">No repositories</span>
+										) : (
+											project.repositories.map((repo) => (
+												<span key={repo.id} className="mobile-list-item-chip">
+													{repo.name}
+												</span>
+											))
+										)}
+									</div>
+								</div>
+							);
+						}}
 						onItemClick={(id) => {
 							const project = projects.find((p) => p.id === id);
 							if (project) {