feat(topics): restore topic taxonomy workflow

tests/front-submit/topics-harness.php

@@ -0,0 +1,48 @@
+<?php
+define('ABSPATH', __DIR__);
+
+class WP_Term {
+	public function __construct(
+		public int $term_id,
+		public int $parent,
+		public string $name
+	) {}
+}
+
+function absint($value): int { return abs((int) $value); }
+function esc_attr($value): string { return htmlspecialchars((string) $value, ENT_QUOTES, 'UTF-8'); }
+function esc_html($value): string { return htmlspecialchars((string) $value, ENT_QUOTES, 'UTF-8'); }
+function get_terms(array $args): array {
+	if ($args['taxonomy'] !== 'topics') return [];
+	return [new WP_Term(1, 0, 'Parent'), new WP_Term(2, 1, 'Child'), new WP_Term(3, 1, 'Sibling'), new WP_Term(4, 0, 'Other')];
+}
+function get_term_children(int $id, string $taxonomy): array {
+	return $taxonomy === 'topics' && $id === 1 ? [2, 3] : [];
+}
+function term_exists(int $id, string $taxonomy): bool {
+	return $taxonomy === 'topics' && in_array($id, [1, 2, 3, 4], true);
+}
+
+require dirname(__DIR__, 2) . '/src/Core/SubmitTopics.php';
+require dirname(__DIR__, 2) . '/templates/parts/submit/term-checks.php';
+
+$root = ['allow_topics' => true, 'allowed_topic_ids' => [1]];
+$child = ['allow_topics' => true, 'allowed_topic_ids' => [2]];
+$disabled = ['allow_topics' => false, 'allowed_topic_ids' => []];
+$tree = static fn(array $settings): array => array_map(
+	static fn(array $node): array => ['id' => $node['term']->term_id, 'depth' => $node['depth']],
+	\Jio\Core\SubmitTopics::tree($settings)
+);
+
+ob_start();
+jio_submit_render_term_checks([new WP_Term(2, 1, 'Child')], [], 'topics');
+$orphan_html = ob_get_clean();
+
+echo json_encode([
+	'root_tree' => $tree($root),
+	'child_tree' => $tree($child),
+	'disabled_tree' => $tree($disabled),
+	'filtered' => \Jio\Core\SubmitTopics::filter_ids([2, 4, 999, 2], $child),
+	'disabled_filtered' => \Jio\Core\SubmitTopics::filter_ids([2], $disabled),
+	'orphan_html' => $orphan_html,
+], JSON_THROW_ON_ERROR);