a11y: Touch-Target System mit Token-basierter Sizing (Redesign Phase E)

- Neue Tokens: --target-sm (32px), --target-md (40px), --target-lg (48px)
- Globale min-height:44px Regel aus reset.css entfernt
- Alle 28 min-height:unset Overrides eliminiert
- Strategy A: Buttons, Nav-Items, Inputs → 48px mobile, 40px desktop
- Strategy B: Kleine Elemente (Checkboxen, Swatches, Delete-Buttons)
  → ::before Pseudo-Element expandiert Touch-Area auf 48×48px

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

public/styles/calendar.css

@@ -79,7 +79,7 @@
   color: var(--color-text-secondary);
   cursor: pointer;
   transition: all var(--transition-fast);
-  min-height: unset;
+  min-height: var(--target-lg);
   white-space: nowrap;
 }
 
@@ -530,6 +530,14 @@
   border: 2px solid transparent;
   cursor: pointer;
   transition: transform var(--transition-fast), border-color var(--transition-fast);
+  position: relative;
+}
+
+.color-swatch::before {
+  content: '';
+  position: absolute;
+  inset: -10px;
+  border-radius: var(--radius-full);
 }
 
 .color-swatch:hover {