fix: bookmark widget sizing, generic globe icon, code-server brand icon

- multi-link bookmark cards now span 4/2 (matching the system widget)
  instead of 3/1, so they're not cramped and line up into an even
  3-up row alongside it
- the link list scrolls internally instead of stretching the card,
  so widgets in the same row stay equal height regardless of link count
- BrandIcon gains a small "generic icon" escape hatch (currently just
  `globe`, via phosphor) for widgets that don't have a real brand mark
- added a `coder` brand icon (Coder/code-server) for the Code Server link,
  since simple-icons has no official VS Code mark to use

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WpxhtQY3CExQdMs4j7MmJe

components/widgets/BrandIcon.tsx

@@ -1,7 +1,20 @@
+import { GlobeSimple } from "@phosphor-icons/react/ssr";
 import { BRAND_ICON_PATHS } from "@/lib/brand-icons";
 
+// Generic (non-brand) icons that don't belong in BRAND_ICON_PATHS - for
+// widgets that link to something with no single logo of its own.
+const GENERIC_ICONS = {
+  globe: GlobeSimple,
+};
+
 export function BrandIcon({ slug, size = 18 }: { slug?: string; size?: number }) {
   if (!slug) return null;
+
+  const GenericIcon = GENERIC_ICONS[slug as keyof typeof GENERIC_ICONS];
+  if (GenericIcon) {
+    return <GenericIcon size={size} className="shrink-0 text-fg-muted" aria-hidden />;
+  }
+
   const path = BRAND_ICON_PATHS[slug];
   if (!path) return null;