fix(desktop): prevent URL highlight from bleeding past link boundary (#452)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

desktop/src/features/messages/lib/useRichTextEditor.ts

@@ -183,7 +183,11 @@ export function useRichTextEditor({
         Placeholder.configure({
           placeholder: () => placeholderRef.current ?? "Write a message…",
         }),
-        Link.configure({
+        Link.extend({
+          inclusive() {
+            return false;
+          },
+        }).configure({
           openOnClick: false,
           autolink: true,
           linkOnPaste: true,