Fix jumpToParagraph: use Milkdown editorViewCtx instead of CSS selector

Co-Authored-By: Claude Sonnet 4.6 <[e-mail]>

templates/document_edit.html

···
         if (pid === 'general') return;
         const idx = parseInt(pid.replace('p-', ''), 10);
         if (isNaN(idx)) return;
-        const pmEl = document.querySelector('#editor-rich .ProseMirror');
-        if (!pmEl) return;
+        if (!milkdownEditor) return;
+        const pmView = milkdownEditor.action(ctx => ctx.get(editorViewCtx));
+        if (!pmView) return;
+        const pmEl = pmView.dom;
         const blocks = Array.from(pmEl.children);
         const target = blocks[idx];
         if (!target) return;