feat(repositories): add favorite repositories feature

This update introduces a favorites system for repositories, allowing users
to mark certain repositories as favorites for easier access. The UI has been
modified to include a star icon for toggling favorites, and the layout has
been adjusted to display favorite repositories separately.

- Implemented favorite repository management with local storage
- Updated UI to show favorite repositories with a star icon
- Enhanced repository listing to filter and display favorites

src/app.css

@@ -782,7 +782,7 @@
   }
   .repo-row {
     display: grid;
-    grid-template-columns: minmax(0, 1fr) auto;
+    grid-template-columns: minmax(0, 1fr) auto auto;
     align-items: stretch;
     min-height: 36px;
     border-bottom: 1px solid rgba(255,255,255,0.035);
@@ -852,6 +852,12 @@
     background: transparent;
     color: var(--color-ink-faint);
   }
+  .repo-row-favorite.active {
+    color: #e0c15f;
+  }
+  .repo-row-favorite.active svg {
+    fill: currentColor;
+  }
 
   /* --- Notices --- */