feat: replace notifications with import status in profile dropdown

Remove the notification system entirely and show import progress
directly in the user dropdown menu. Block new imports while one
is already running.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

assets/styles/app.css

@@ -363,35 +363,31 @@ body {
     margin: 0;
 }
 
-/* ── Notifications ── */
+/* ── Import status ── */
 
-.notifications-list {
-    max-height: 300px;
-    overflow-y: auto;
+.import-status-item {
+    display: flex;
+    flex-direction: column;
 }
 
-.notification-item {
-    padding: 10px 16px;
-    border-bottom: 1px solid var(--surface-warm);
-}
-
-.notification-item:last-child {
-    border-bottom: none;
-}
-
-.notification-item p {
-    margin: 0 0 3px;
-    font-size: 13px;
-    color: var(--text);
-}
-
-.notification-item time {
+.import-status-text {
+    display: block;
+    padding: 0 12px 8px;
     font-size: 11px;
-    color: var(--text-faint);
+    font-weight: 500;
+    line-height: 1.3;
 }
 
-.notification-unread {
-    background: var(--surface-warm);
+.import-status-active {
+    color: var(--orange);
+}
+
+.import-status-completed {
+    color: #16a34a;
+}
+
+.import-status-failed {
+    color: #dc2626;
 }
 
 /* ── Modal ── */
@@ -595,6 +591,20 @@ body {
     font-size: 16px;
 }
 
+.start-loader {
+    display: none;
+    width: 48px;
+    height: 48px;
+    border: 4px solid rgba(255, 255, 255, 0.15);
+    border-top-color: #ff6b81;
+    border-radius: 50%;
+    animation: spin 0.7s linear infinite;
+}
+
+@keyframes spin {
+    to { transform: rotate(360deg); }
+}
+
 /* ── Game footer ── */
 
 .game-footer {