- pets/[petId]/page.tsx: replace /api/avatar stub with NEXT_PUBLIC_R2_PUBLIC_URL CDN URL
- pets/[petId]/edit/page.tsx: pass initialAvatarKey to PetForm so AvatarUpload shows current photo
- Sidebar.tsx: add avatarKey to Pet type; show AvatarImage from CDN for active pet and dropdown list
- MobileNav.tsx: same CDN avatar pattern for mobile pet switcher
- next.config.ts: add images.remotePatterns for R2 CDN hostname (T-4-04 safeguard)
- (app)/layout.tsx: server component with auth() check + pets.list + redirect to /onboarding/pet if no pets
- Sidebar.tsx: 240px desktop nav (lg:), pet switcher with active state, nav links with orange-500 active indicator
- MobileNav.tsx: fixed bottom bar (h-16, lg:hidden), pet switcher above tabs, orange-500 center post button
- onboarding/pet/page.tsx: stub with Plan 03 placeholder (replaces walking skeleton client form)
- Deviation: base-nova shadcn uses @base-ui/react/menu (no asChild support) — used onClick+useRouter
- Deviation: Clerk 7 UserButton no longer accepts afterSignOutUrl