fix(docs): access node.attrs for lock toggle state detection

getStructuredContentTags returns {node, pos} objects — attrs are on
node.attrs, not directly on the object.

Author: tupizz

apps/docs/snippets/extensions/structured-content.mdx

@@ -74,8 +74,8 @@ import { SuperDocEditor } from '/snippets/components/superdoc-editor.jsx'
           const editor = superdoc?.activeEditor || superdoc?.editor
           if (!editor?.commands) return
           const tags = editor.helpers.structuredContentCommands.getStructuredContentTags(editor.state)
-          const field = tags.find(t => String(t.id) === '1')
-          const locked = field?.lockMode && field.lockMode !== 'unlocked'
+          const field = tags.find(t => String(t.node.attrs.id) === '1')
+          const locked = field?.node.attrs.lockMode && field.node.attrs.lockMode !== 'unlocked'
           editor.commands.updateStructuredContentById('1', {
             attrs: { lockMode: locked ? 'unlocked' : 'sdtContentLocked' },
           });
@@ -87,8 +87,8 @@ import { SuperDocEditor } from '/snippets/components/superdoc-editor.jsx'
           const editor = superdoc?.activeEditor || superdoc?.editor
           if (!editor?.commands) return
           const tags = editor.helpers.structuredContentCommands.getStructuredContentTags(editor.state)
-          const field = tags.find(t => String(t.id) === '2')
-          const locked = field?.lockMode && field.lockMode !== 'unlocked'
+          const field = tags.find(t => String(t.node.attrs.id) === '2')
+          const locked = field?.node.attrs.lockMode && field.node.attrs.lockMode !== 'unlocked'
           editor.commands.updateStructuredContentById('2', {
             attrs: { lockMode: locked ? 'unlocked' : 'sdtContentLocked' },
           });