feat(links): move friend links to native WordPress links with review flow

- enable the native Links manager and drop the custom friend-link option/REST path
- add per-page link settings for the friends template
- render link categories from get_bookmarks() with search and page-content options
- add a validated public link submission endpoint with logo upload, captcha, rate limiting and duplicate checks
- create pending links for review and notify administrators by email and in-app message
- add native Links admin pending count, columns and edit notes
- cover the new submission and cleanup contracts

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

assets/css/routes/links.css

@@ -148,6 +148,17 @@
 	margin-bottom: 6px;
 }
 
+.jio-links-submit-status {
+	margin: 10px 0;
+	font-size: 0.92em;
+}
+
+.jio-links-logo-preview {
+	width: 88px;
+	height: 88px;
+	object-fit: cover;
+}
+
 /* ---- search cover ---- */
 .link-page-search-cover.page-cover {
 	position: relative;