design: Frontend-Redesign v2 — Design-System, kompaktere UI, Mikrointeraktionen

Umfassendes Redesign des gesamten Frontends in 9 Schritten:

1. Design-Tokens: Neutral-Farbskala (50–950), Modul-Akzentfarben,
   --text-2xs Token, Easing-Kurven, Z-Index-System, Dark-Mode-Overrides
2. Reset: Reduced-motion Query (prefers-reduced-motion)
3. Sidebar/Navigation: Flaches Design, Glassmorphismus Bottom-Nav,
   Akzentstreifen-Indikator, collapsed/expanded States
4. Layout-Grid: Master-Detail, Content-Aside, Sticky-Header-Primitives
5. Cards/Container: Einheitliches Card-Pattern, Modal-System (Bottom-Sheet
   mobil, zentriert Desktop), Skeleton-Loading, Empty-States
6. Dashboard: Kompaktere Widgets, Token-basierte Farben/Schatten,
   4-Spalten-Grid ab 1440px
7. Module: Mobile-first Kanban/Day-Slots/Budget-Summary, border-subtle
   für sekundäre Trennlinien, responsive Quick-Add, Token-Migration
   aller hardcoded px/rgba-Werte
8. Mikrointeraktionen: Page-out Fade, Checkbox-Pop-Animation,
   Hover-States für Filter/Tabs/Toggles, Toast-Ausblendung,
   done-State Opacity-Transition
9. Feinschliff: Print-Styles, --text-2xs Token für Micro-Labels,
   Konsistenz-Audit (alle 9/10/11px → Token)

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

public/styles/contacts.css

@@ -98,6 +98,11 @@
   min-height: 30px;
 }
 
+.contact-filter-chip:hover:not(.contact-filter-chip--active) {
+  border-color: var(--color-text-secondary);
+  color: var(--color-text-primary);
+}
+
 .contact-filter-chip--active {
   background-color: var(--color-accent);
   border-color: var(--color-accent);
@@ -136,7 +141,7 @@
   align-items: center;
   gap: var(--space-3);
   padding: var(--space-3) var(--space-4);
-  border-bottom: 1px solid var(--color-border);
+  border-bottom: 1px solid var(--color-border-subtle);
   cursor: pointer;
   transition: background-color var(--transition-fast);
 }
@@ -231,7 +236,7 @@
 .contact-modal-overlay {
   position: fixed;
   inset: 0;
-  background-color: rgba(0,0,0,0.5);
+  background-color: var(--color-overlay);
   z-index: var(--z-modal);
   display: flex;
   align-items: flex-end;