Body-Nav entfernen, Dashboard-Header mit Titel und Einstellungen-Link

- <nav id='nav'> samt nav.css komplett entfernt
- Nav-Link-Logik aus app.js und router.js entfernt
- Nav-Hide aus mobile.css entfernt
- Dashboard-Template: Header mit Titel '// gott' und Link 'Einstellungen'
- Dashboard CSS: .dashboard-header mit Flex-Layout
- Einstellungen-Link navigiert zur Settings-Page

wwwroot/css/dashboard.css

@@ -2,6 +2,29 @@
   padding: var(--page-padding);
 }
 
+.dashboard-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  margin-bottom: var(--page-spacing);
+}
+
+.dashboard-title {
+  margin: 0;
+}
+
+.dashboard-link {
+  color: var(--text);
+  text-decoration: none;
+  opacity: var(--semi-transparent);
+  transition: opacity var(--transition-duration);
+}
+
+.dashboard-link:hover {
+  opacity: 1;
+  color: var(--text-accent);
+}
+
 .dashboard section {
   margin-bottom: var(--page-spacing);
   width: 100%;

wwwroot/css/mobile.css

@@ -1,8 +1,5 @@
 /* === Mobile === */
 @media (max-width: 768px) {
-  #nav {
-    display: none;
-  }
   .msg, .tool-box {
     max-width: 100%;
   }

wwwroot/css/nav.css

@@ -1,41 +0,0 @@
-#nav {
-  border-bottom: var(--border-width) solid var(--f2-border);
-  flex-shrink: 0;
-  display: flex;
-  justify-content: center;
-}
-
-.nav-content {
-  display: flex;
-  align-items: center;
-  gap: var(--page-spacing);
-  width: var(--page-width);
-  max-width: 100%;
-  padding: var(--box-padding);
-  transition: var(--transition-duration);
-}
-
-.nav-brand,
-.nav-link {
-  padding: var(--badge-padding);
-  color: var(--text);
-  border-bottom: 2px solid transparent;
-}
-
-.nav-links {
-  display: flex;
-  gap: var(--box-spacing);
-}
-
-.nav-link {
-  text-decoration: none;
-}
-
-.nav-link:hover {
-  color: var(--text-accent);
-}
-
-.nav-link.active {
-  color: var(--text-accent);
-  border-bottom-color: var(--primary);
-}