Clean up dashboard ui and remove channels page

src/main/resources/static/css/styles.css

@@ -860,6 +860,17 @@ button:disabled:hover {
     gap: 20px;
 }
 
+.dashboard-grid {
+    display: grid;
+    gap: 20px;
+    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
+    align-items: start;
+}
+
+.dashboard-span-full {
+    grid-column: 1 / -1;
+}
+
 .dashboard-topbar {
     display: flex;
     align-items: center;
@@ -955,6 +966,77 @@ button:disabled:hover {
     font-size: 12px;
 }
 
+.dashboard-tile-grid {
+    display: grid;
+    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
+    gap: 12px;
+    margin-top: 12px;
+}
+
+.dashboard-tile {
+    display: flex;
+    flex-direction: column;
+    gap: 8px;
+    padding: 16px;
+    border-radius: 12px;
+    border: 1px solid rgba(148, 163, 184, 0.35);
+    background: rgba(15, 23, 42, 0.75);
+    color: #e2e8f0;
+    text-decoration: none;
+    min-height: 140px;
+    transition:
+        border-color 0.2s ease,
+        background-color 0.2s ease,
+        transform 0.2s ease;
+}
+
+.dashboard-tile:hover,
+.dashboard-tile:focus-visible {
+    border-color: rgba(226, 232, 240, 0.7);
+    background: rgba(30, 41, 59, 0.8);
+    transform: translateY(-1px);
+}
+
+.dashboard-tile .tile-icon {
+    min-width: 44px;
+    height: 44px;
+    border-radius: 10px;
+    display: grid;
+    place-items: center;
+    background: rgba(124, 58, 237, 0.18);
+    color: #c4b5fd;
+    font-weight: 700;
+    font-size: 12px;
+    text-transform: uppercase;
+    letter-spacing: 0.5px;
+}
+
+.dashboard-tile .tile-title {
+    font-weight: 600;
+    font-size: 15px;
+}
+
+.dashboard-tile .tile-subtitle {
+    color: #cbd5e1;
+    font-size: 12px;
+    line-height: 1.4;
+}
+
+.dashboard-toggle-tile {
+    cursor: pointer;
+}
+
+.dashboard-toggle-tile .tile-row {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    width: 100%;
+}
+
+.dashboard-toggle-tile input[type="checkbox"] {
+    margin-left: auto;
+}
+
 .user-display {
     font-weight: 700;
     color: #e2e8f0;