test(plugin-detail): type the markdown editor's onChange and the highlight fixtures (objectui#11541)

Drops two `as any` casts in the new pin file (a plain name/label pair is a
HighlightField) and the `any` on the markdown branch's onChange parameter,
which TextAreaField already types as string. No behaviour change.

Claude-Session: https://claude.ai/code/session_01FjqrwXPfSMkSfkKYDSRkN2
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

packages/plugin-detail/src/InlineFieldInput.tsx

@@ -422,7 +422,7 @@ export const InlineFieldInput: React.FC<InlineFieldInputProps> = ({
   // `html` / `richtext` never reach this component: the hosts' gate still
   // excludes them.
   if (editType === 'markdown') {
-    return <TextAreaField field={field as any} value={value} onChange={(v: any) => onChange(v)} autoFocus={autoFocus} error={error} />;
+    return <TextAreaField field={field as any} value={value} onChange={(v) => onChange(v)} autoFocus={autoFocus} error={error} />;
   }
   // Reference fields (lookup / master_detail / tree / user / owner) store an id
   // but may arrive `$expand`-ed as a record object. A plain text input would

packages/plugin-detail/src/__tests__/InlineFieldInput.markdownEditor-11541.test.tsx

@@ -129,7 +129,7 @@ describe('objectui#11541 — both detail hosts offer the markdown editor', () =>
     }
     const { container } = render(
       <InlineEditProvider canEdit>
-        <HeaderHighlight fields={[{ name: 'notes', label: 'Notes' }] as any} data={{ notes: STORED }} objectSchema={markdownSchema} />
+        <HeaderHighlight fields={[{ name: 'notes', label: 'Notes' }]} data={{ notes: STORED }} objectSchema={markdownSchema} />
         <EnterEdit />
       </InlineEditProvider>,
     );
@@ -232,7 +232,7 @@ describe('objectui#11541 — `html` and `richtext` still open no editor', () =>
       const { container } = render(
         <InlineEditProvider canEdit>
           <HeaderHighlight
-            fields={[{ name: 'body', label: 'Body' }] as any}
+            fields={[{ name: 'body', label: 'Body' }]}
             data={{ body: MARKUP[type] }}
             objectSchema={{ fields: { body: { type, label: 'Body' } } }}
           />