feat(users): govern profiles and access

Normalize fixed profile fields, profile actions, and the five-column capability matrix for comments, uploads, and downloads.

templates/parts/submit/context.php

@@ -213,9 +213,9 @@ return [
 	'can_cover_image'    => $cap('new_post_image_cover'),
 	'can_cover_slide'    => $cap('new_post_slide_cover'),
 	'can_cover_video'    => $cap('new_post_video_cover'),
-	'can_upload_img'     => $cap('new_post_upload_img'),
+	'can_upload_img'     => $cap('upload_submit_image'),
 	'can_upload_video'   => $cap('new_post_upload_video'),
-	'can_upload_file'    => $cap('new_post_upload_file'),
+	'can_upload_file'    => $cap('upload_resource_attachment'),
 	'can_hide'           => $cap('new_post_hide'),
 	'can_iframe'         => $cap('new_post_iframe_video'),
 ];