fix: autoSave not defined in title input — use save() directly

The @input handler on the title called autoSave() which wasn't in
scope. Changed to save() which is available on the Alpine x-data object.
The debounce is already handled internally.

app/templates/page_editor.html

@@ -206,7 +206,7 @@
     <div class="page-title-block">
       <span class="page-icon-emoji">📄</span>
       <div class="page-title-input" contenteditable="true" id="_titleEl"
-           @input="dirty=true;autoSave()"
+           @input="dirty=true;save()"
            @keydown.enter.prevent="focusBlock()"
            @paste.prevent="pastePlain($event)"
            spellcheck="false">{{ page.title }}</div>