fix(report): give preset reasons a stable non-empty slug for CJK labels

ban_settings() derived each reason slug via sanitize_key(label), which
strips CJK text to an empty string; the frontend filter then discarded
every reason (including the schema defaults) and fell back to the
hard-coded list. Derive the slug from an ASCII key when possible and
from a stable md5 short hash of the label otherwise, and relax the
frontend filter to the label only. Adds a WP-stub harness that verifies
the defaults path end to end (tests/dev/verify-ban-settings-defaults.php).

tests/dev/verify-ban-settings-defaults.php

@@ -0,0 +1,73 @@
+<?php
+/**
+ * Local harness: verify UserRuntime::ban_settings() returns the schema
+ * default preset reasons when the option is empty (never saved).
+ * Run: php tests/dev/verify-ban-settings-defaults.php
+ */
+
+error_reporting(E_ALL & ~E_DEPRECATED);
+
+// ---- WP stubs ----
+$GLOBALS['__test_options'] = [];
+function get_option($key, $default = false) {
+    return $GLOBALS['__test_options'][$key] ?? $default;
+}
+function update_option($key, $value) { $GLOBALS['__test_options'][$key] = $value; return true; }
+function sanitize_key($key) { return preg_replace('/[^a-z0-9_\-]/', '', strtolower((string) $key)); }
+function sanitize_text_field($value) { return trim(strip_tags((string) $value)); }
+function sanitize_textarea_field($value) { return trim(strip_tags((string) $value)); }
+function wp_kses_post($value) { return (string) $value; }
+function __($text, $domain = null) { return $text; }
+function esc_html__($text, $domain = null) { return $text; }
+function esc_attr__($text, $domain = null) { return $text; }
+function apply_filters($tag, $value) { return $value; }
+function add_filter(...$args) {}
+function do_action(...$args) {}
+function add_action(...$args) {}
+function get_current_user_id() { return 1; }
+function is_user_logged_in() { return true; }
+function wp_unslash($value) { return $value; }
+function current_time($type) { return date('Y-m-d H:i:s'); }
+function get_theme_file_uri($file = '') { return 'https://example.test/wp-content/themes/aksrt/' . ltrim((string) $file, '/'); }
+function get_theme_file_path($file = '') { return dirname(__DIR__, 2) . '/' . ltrim((string) $file, '/'); }
+function get_template_directory() { return dirname(__DIR__, 2); }
+function esc_url_raw($url) { return (string) $url; }
+function esc_html($text) { return (string) $text; }
+function esc_attr($text) { return (string) $text; }
+
+define('ABSPATH', __DIR__ . '/');
+
+$repo = dirname(__DIR__, 2);
+
+foreach (['DomainGroups', 'DisplayPageGroups', 'CreditsPaymentGroups', 'CategoryIntegrationGroups', 'AuthReader', 'HomepageReader', 'FacadeBulk'] as $trait_file) {
+    require $repo . '/src/Settings/' . $trait_file . '.php';
+}
+require $repo . '/src/Admin/Schema/SchemaUsers.php';
+require $repo . '/src/Admin/SchemaProvider.php';
+require $repo . '/src/Settings/Settings.php';
+require $repo . '/src/Settings/UserRuntime.php';
+
+$reasons = \AKSRT\Settings\UserRuntime::ban_settings()['reasons'] ?? null;
+$report  = \AKSRT\Settings\UserRuntime::report_settings();
+
+echo "=== ban_settings()['reasons'] (empty option) ===\n";
+var_export($reasons);
+echo "\n\n=== report_settings() ===\n";
+var_export([
+    'enabled'     => $report['enabled'] ?? null,
+    'img_enabled' => $report['img_enabled'] ?? null,
+    'desc_len'    => isset($report['desc']) ? strlen($report['desc']) : null,
+]);
+
+// 再模拟“后台保存过自定义原因”的场景
+$GLOBALS['__test_options']['aksrt_settings'] = [
+    'ban_preset_reason' => [
+        ['t' => '自定义原因A'],
+        ['t' => '自定义原因B'],
+    ],
+];
+\AKSRT\Settings\Settings::flush_settings_cache();
+$stored = \AKSRT\Settings\UserRuntime::ban_settings()['reasons'] ?? null;
+echo "\n\n=== ban_settings()['reasons'] (custom stored) ===\n";
+var_export($stored);
+echo "\n";