feat(pmr): configure design system foundation

Task 1: Design system foundation and font setup
- Add Geist Mono font to Google Fonts import for PMR coded entries and timestamps
- Extend PMR color tokens in Tailwind config (card, text variants, borders, alert colors)
- Update border-radius defaults: 4px for cards/inputs, 12px for login card
- Add PMR-specific CSS custom properties in index.css
- Add .pmr-theme, .font-inter, .font-geist-mono utility classes
- Add pmr shadow token (minimal clinical system shadow)

All PMR color tokens now match ref-design-system.md spec exactly.

tailwind.config.js

@@ -37,10 +37,21 @@ export default {
           sidebar: '#1E293B',
           banner: '#334155',
           content: '#F5F7FA',
+          card: '#FFFFFF',
           nhsblue: '#005EB8',
           green: '#22C55E',
           amber: '#F59E0B',
           red: '#EF4444',
+          'text-primary': '#111827',
+          'text-secondary': '#6B7280',
+          'text-on-dark': '#FFFFFF',
+          'text-on-dark-secondary': '#94A3B8',
+          'border': '#E5E7EB',
+          'border-dark': '#D1D5DB',
+          'selected-row': '#EFF6FF',
+          'alert-bg': '#FEF3C7',
+          'alert-border': '#F59E0B',
+          'alert-text': '#92400E',
         },
       },
       fontFamily: {
@@ -54,9 +65,11 @@ export default {
         'sm': '0 1px 3px rgba(0,0,0,0.06)',
         'md': '0 4px 12px rgba(0,0,0,0.08)',
         'lg': '0 8px 24px rgba(0,0,0,0.1)',
+        'pmr': '0 1px 2px rgba(0,0,0,0.03)',
       },
       borderRadius: {
-        'card': '16px',
+        'card': '4px',
+        'login': '12px',
       },
     },
   },