fix(widgets): restore single-card reference UI for search and quote widgets

The 搜索框 and 一言 sidebar widgets fell into the generic renderer branch, so
they rendered a .jio-panel card wrapping a second bespoke card
(.jio-widget-search / .jio-widget-quote). In-article 一言 also used
divergent modifier classes and an extra hover rule.

- search: render through the shared jio_get_search_box() (legacy keyword,
  history and category pickers) inside one reference card, mirroring the
  reference widget's markup and title default 「搜索」
- quote: render the reference .yiyan-box card itself as the click root; the
  shell now emits only the reference widget-container/title wrapper
- article 一言: adopt the reference class lists for header, footer and the
  standalone after-article box; drop the invented yiyan--* modifiers and
  the duplicate hover/opacity rules
- client: fill .cn/.en in the reference order (first line .cn, second .en)
  and drop the stale window.JioYiyan bridge plus the dead qv-yiyan.php AJAX
  path in runtime main.js
- schema: replace the ad-hoc search_style radio with the reference switches
  (keywords, history, input category, more_cats) and default title
- assets: enqueue assets/js/yiyan.js through the quote widget's asset list

Tests: widget-system suite 820/821 (the one failure is the pre-existing
frontend-lifecycle theme-init stub); new search/quote card contracts pass.

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

tests/widget-system/search-quote-render-harness.php

@@ -0,0 +1,44 @@
+<?php
+/**
+ * Render the search and quote widgets through production code and report the
+ * markup, so the contract test can assert the reference single-card shell.
+ */
+declare(strict_types=1);
+
+namespace Jio\WidgetSystem {
+	final class AssetManager {
+		public static function enqueue_for(WidgetDefinition $definition): void {}
+	}
+}
+
+namespace {
+	require __DIR__ . '/bootstrap.php';
+
+	use Jio\WidgetSystem\SchemaWidget;
+	use Jio\WidgetSystem\WidgetDefinition;
+	use Jio\WidgetSystem\WidgetRegistry;
+
+	if (!function_exists('jio_get_search_box')) {
+		function jio_get_search_box(array $args = [], bool $echo = false) {
+			return '<div class="search-input"><form class="search-form"></form></div>';
+		}
+	}
+	if (!function_exists('jio_get_yiyan_markup')) {
+		function jio_get_yiyan_markup(array $args = []): string {
+			return '<div class="' . esc_attr((string) ($args['class'] ?? 'jio-yiyan')) . ' jio-yiyan" data-jio-yiyan><div class="yiyan"></div></div>';
+		}
+	}
+
+	$cases = [];
+	foreach (['search', 'quote'] as $slug) {
+		$definition = WidgetRegistry::get($slug);
+		$widget = new SchemaWidget($definition);
+		$widget->_set(1);
+		$instance = $definition->normalize(['title' => '示例标题', 'placeholder' => '开启精彩搜索']);
+		ob_start();
+		$widget->widget(['before_widget' => '<section class="jio-widget-shell">', 'after_widget' => '</section>'], $instance);
+		$cases[$slug] = (string) ob_get_clean();
+	}
+
+	echo json_encode($cases, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR);
+}