feat: groups home page with authenticated layout shell

[kevinrutledge]

Developer

Kevin Rutledge

Closes #87

What changed?

• Replaced (protected) layout header with sidebar + top bar layout shell using TopBarActionProvider context for per-page action buttons
• Created groups page at /groups with 3-column card grid, role-based data fetching (admin sees all groups, member sees own groups), and full modal state machine (detail → edit → delete/add members, create)
• Wired all group modals to server actions (createContactGroup, updateContactGroup, deleteContactGroup, addMembers) with loading states, toast notifications, and data refresh
• Added fetchEnrichedGroup server action for on-demand member detail loading when clicking a group card
• Updated navigation.ts with Messages, Events, Settings routes
• Moved mock portal to (dev) route group to avoid inheriting public layout, redesigned to match real Paso Food Co-op portal
• Added Playwright e2e test suite (24 tests) covering group CRUD flows, modal navigation chains, and auth setup with admin/member storage state

How to test

1. Run npm run build - should pass
2. Run npm run dev and navigate to /dev/mock-portal - login as admin (100001)
3. Navigate to /groups - see card grid with "Groups" heading and sidebar/top bar layout
4. Click a group card → detail modal shows name, description, members
5. Detail → Edit → modify name → Save Changes → toast + card updates
6. Edit → Delete → Confirm → toast + card removed
7. Edit → Add Members → select members → Save → members updated
8. Click add card or "+ New Group" in top bar → create modal → submit → new card appears
9. Login as member (100003) - see "My Groups" heading with only owned groups
10. Run npx playwright test - all e2e tests pass

Checklist

• Code works and is readable
• Tested locally
• Commits follow conventional commits
• Assigned reviewers