fix(editor): prevent link mark from sticking to cursor

Override Link extension `inclusive: false` via `.extend()` to decouple
it from `autolink: true`. Tiptap's source ties `inclusive` to `autolink`,
causing typed text after a link to inherit the link mark.

Also set `linkOnPaste: false` — autolink's PasteRule still auto-detects
pasted URLs without the sticky cursor issue.

Refs: ueberdosis/tiptap#2571, ueberdosis/tiptap#4249

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

apps/web/components/common/rich-text-editor.tsx

@@ -50,9 +50,10 @@ interface RichTextEditorRef {
   insertFile: (filename: string, url: string, isImage: boolean) => void;
 }
 
-const LinkExtension = Link.configure({
+const LinkExtension = Link.extend({ inclusive: false }).configure({
   openOnClick: true,
   autolink: true,
+  linkOnPaste: false,
   HTMLAttributes: {
     class: "text-primary hover:underline cursor-pointer",
   },