fix(admin): improve native link manager filters

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

assets/css/admin/links-manager.css

@@ -0,0 +1,30 @@
+/* Keep the native category filter useful even before links are assigned. */
+#cat_id {
+	min-width: 180px;
+}
+
+/* The pending count lengthens this sortable header beyond WordPress's default 8% column. */
+.wp-list-table th.column-visible {
+	width: 170px;
+	min-width: 170px;
+}
+
+.wp-list-table th.column-visible a {
+	display: inline-flex;
+	align-items: center;
+	gap: 4px;
+	white-space: nowrap;
+}
+
+.wp-list-table th.column-visible a > span {
+	float: none;
+}
+
+.wp-list-table th.column-visible .sorting-indicators {
+	display: grid;
+	flex: 0 0 auto;
+}
+
+.wp-list-table th.column-visible .sorting-indicator {
+	margin-left: 0;
+}