Compliance: Remove emojis, add touch targets, add reduced-motion support

No-Emoji Policy (TODO.md rule):
- Replaced all emojis in UI code with Lucide icon names or text:
  - calendar-manager.ts: exam/lesson/holiday/term/event icons
  - signage-utils.ts: emergency/notification/schedule/announcement icons
  - behavior-tracking-view.tsx: placeholder text
  - i18n.ts: example text strings (DE + EN)
  - admin/signage, admin/compliance pages
  - compliance-wizard.tsx, substitute-teacher-view.tsx
- Verified: zero emojis remain in src/ (excluding comments)

Touch Target Compliance (44px minimum):
- Added comprehensive @media (pointer: coarse) CSS rules:
  - All buttons, [role=button], [role=tab], [role=option], [role=menuitem]
    get min-height/min-width: 44px
  - Icon-only buttons get extra padding
  - -webkit-touch-callout: none and user-select: none for buttons
  - touch-action: manipulation for smooth scrolling

Reduced-Motion Support:
- Added comprehensive @media (prefers-reduced-motion: reduce) rules:
  - All animations: duration 0.01ms, iteration 1
  - All transitions: duration 0.01ms
  - scroll-behavior: auto (no smooth scroll)
  - Framer-motion elements: opacity 1, transform none

src/app/admin/signage/page.tsx

@@ -184,7 +184,7 @@ export default function SignageAdminPage() {
                       label: 'Sound',
                       render: (_, row) => (
                         <span className={row.soundAlert ? 'text-amber-600' : 'text-gray-400'}>
-                          {row.soundAlert ? '🔊' : '🔇'}
+                          {row.soundAlert ? 'volume-up' : 'volume-off'}
                         </span>
                       ),
                     },