fix(admin): center empty-state placeholder in Image/File/media picker fields (emdash-cms#1940)

* fix(admin): center empty-state placeholder in image/file/media picker fields

The kumo Button's base classes are 'flex w-max items-center' with no
horizontal justification — fine when the button hugs its content, but the
image/file placeholder buttons stretch it with w-full, leaving the icon
and label pinned to the left edge. SeoImageField already carried an
explicit justify-center for exactly this reason; apply the same class to
the three placeholders that lacked it (image field, file field, and the
block-kit media picker).

Fixes emdash-cms#1934

* chore: add changeset for the placeholder centering fix

---------

Co-authored-by: Matt Kane <mkane@cloudflare.com>

Author: 2 people

.changeset/center-media-placeholders.md

@@ -0,0 +1,5 @@
+---
+"@emdash-cms/admin": patch
+---
+
+Centers the empty-state placeholder labels in Image, File, and media picker fields.

packages/admin/src/components/BlockKitMediaPickerField.tsx

@@ -123,7 +123,7 @@ export function BlockKitMediaPickerField({
 				<Button
 					type="button"
 					variant="outline"
-					className="w-full h-24 border-dashed"
+					className="w-full h-24 justify-center border-dashed"
 					onClick={() => setPickerOpen(true)}
 				>
 					<div className="flex flex-col items-center gap-1.5 text-kumo-subtle">

packages/admin/src/components/ContentEditor.tsx

@@ -1662,7 +1662,7 @@ function FileFieldRenderer({
 				<Button
 					type="button"
 					variant="outline"
-					className="mt-2 w-full h-32 border-dashed"
+					className="mt-2 w-full h-32 justify-center border-dashed"
 					onClick={() => setPickerOpen(true)}
 					aria-label={t`Select ${label}`}
 				>

packages/admin/src/components/ImageFieldRenderer.tsx

@@ -167,7 +167,7 @@ export function ImageFieldRenderer({
 				<Button
 					type="button"
 					variant="outline"
-					className="mt-2 w-full h-32 border-dashed"
+					className="mt-2 w-full h-32 justify-center border-dashed"
 					onClick={() => setPickerOpen(true)}
 				>
 					<div className="flex flex-col items-center gap-2 text-kumo-subtle">