Fix mobile touch targets in Navigation + Footer (Phase 4 /adapt)

- Navigation: hamburger minWidth/minHeight 44px, drawer items minHeight 44px
- Footer: contact links, link group links, legal links all minHeight 44px
- Footer: tagline maxWidth responsive (100% on xs, 280 on md)
- ProviderCard/VenueCard: no changes needed (card is the touch target, not meta items)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/organisms/Navigation/Navigation.tsx

@@ -110,6 +110,7 @@ export const Navigation = React.forwardRef<HTMLDivElement, NavigationProps>(
                   onClick={handleDrawerToggle}
                   size="medium"
                   edge="start"
+                  sx={{ minWidth: 44, minHeight: 44 }}
                 >
                   <MenuIcon />
                 </IconButton>
@@ -224,6 +225,7 @@ export const Navigation = React.forwardRef<HTMLDivElement, NavigationProps>(
                   sx={{
                     py: 1.5,
                     px: 3,
+                    minHeight: 44,
                     '&:hover': {
                       bgcolor: 'var(--fa-color-brand-100)',
                     },