- Add branding_logo_url, branding_primary_color, branding_company_name columns to Account model
- Add Alembic migration (58e3f27f3e8f) for branding and SSO columns
- Add GET/PATCH /accounts/me/branding endpoints (owner-only for PATCH)
- Add BrandingSettingsPage with logo URL input, color picker, preview section
- Add /account/branding route (ProtectedRoute owner) in router.tsx
- Add Branding link card in AccountSettingsPage
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>