US-031: Responsive testing and fixes for all new components

SubNav: horizontal scroll with hidden scrollbar, 44px touch targets.
DetailPanel: close button enlarged to 44px. Touch target fixes on
CoreSkillsTile, ProjectsTile, and LastConsultationTile interactive elements.

src/components/tiles/CoreSkillsTile.tsx

@@ -71,6 +71,7 @@ function SkillRow({ skill, onClick }: SkillRowProps) {
         alignItems: 'center',
         gap: '10px',
         padding: '8px 10px',
+        minHeight: '44px',
         background: 'var(--bg-dashboard)',
         borderRadius: 'var(--radius-sm)',
         border: '1px solid var(--border-light)',
@@ -234,6 +235,7 @@ function CategorySection({
             gap: '4px',
             marginTop: '8px',
             padding: '4px 0',
+            minHeight: '44px',
             background: 'none',
             border: 'none',
             cursor: 'pointer',

src/components/tiles/LastConsultationTile.tsx

@@ -235,6 +235,7 @@ export const LastConsultationTile: React.FC = () => {
           background: 'transparent',
           border: 'none',
           padding: '6px 0',
+          minHeight: '44px',
           cursor: 'pointer',
           transition: 'color 150ms ease-out',
         }}

src/components/tiles/ProjectsTile.tsx

@@ -42,6 +42,7 @@ function ProjectItem({ project, onClick }: ProjectItemProps) {
         border: '1px solid var(--border-light)',
         borderRadius: 'var(--radius-sm)',
         padding: '10px 12px',
+        minHeight: '44px',
         fontSize: '11.5px',
         color: 'var(--text-primary)',
         transition: 'border-color 0.15s, box-shadow 0.15s',