feat(web): redesign profile page to match design system

- Rewrite Profile.razor to use .page-container, .glass-card, .gm-alert,

  .btn-gm, .status-badge, .empty-state and other standard design system classes

- Replace custom unstyled markup with breadcrumb, page-header, skeleton loaders

- Add .identity-list styles to app.css for linked accounts section

- Unify visual language with Home, Templates and GroupDetails pages

src/GmRelay.Web/wwwroot/app.css

@@ -1449,6 +1449,62 @@ body.telegram-mini-app .session-card-mobile {
     color: var(--accent-secondary);
 }
 
+/* === Identity list (profile page) === */
+.identity-list {
+    display: flex;
+    flex-direction: column;
+    gap: 0.5rem;
+    list-style: none;
+    padding: 0;
+    margin: 0;
+}
+
+.identity-item {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    padding: 0.75rem 1rem;
+    background: var(--bg-surface);
+    border: 1px solid var(--border-color);
+    border-radius: var(--radius-sm);
+    gap: 1rem;
+    transition: background var(--transition-fast);
+}
+
+.identity-item:hover {
+    background: rgba(255, 255, 255, 0.05);
+}
+
+.identity-info {
+    display: flex;
+    align-items: center;
+    gap: 0.75rem;
+    flex-wrap: wrap;
+    flex: 1;
+}
+
+.identity-platform {
+    font-size: 0.75rem;
+    font-weight: 700;
+    text-transform: uppercase;
+    letter-spacing: 0.05em;
+    color: var(--text-muted);
+    background: var(--bg-primary);
+    padding: 0.25rem 0.5rem;
+    border-radius: var(--radius-sm);
+    border: 1px solid var(--border-color);
+}
+
+.identity-name {
+    font-weight: 600;
+    color: var(--text-primary);
+    font-family: 'Jura', sans-serif;
+}
+
+.telegram-widget-wrapper {
+    margin-top: 0.5rem;
+}
+
 /* === Sidebar refinements (MainLayout & NavMenu) === */
 .page {
     display: flex;