refactor(color): unify color sanitizing and picking behind shared components

- Add AKSRT\Core\Color::sanitize($value, $allow_alpha) as the single PHP
  color sanitizer; replace sanitize_hex_color calls and per-class regexes
  (FloatButtons, FieldSchema, ThemeSearch, icon cards, TicketStatusService)
- SchemaProvider / ControllerBase sanitize `color` fields as colors;
  alpha kept only when the schema sets showAlpha
- Split SchemaProvider OAuth validation and option matching into sibling
  traits to stay under the 1000-line limit
- Add AksColorPicker.vue + utils/color.js mirroring the PHP rules; AksField,
  FloatBtnCommonFields and TicketStatusPanel use it
- Widget background color input now uses wpColorPicker
- Remove dead AksCompositeField dimensions/spacing/background branches and
  the unused Gutenberg ColorPicker var
- Add color-unification contract test; update harness requires and tests

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/Settings/DisplayPageGroups.php

@@ -77,7 +77,7 @@ trait DisplayPageGroups {
 			'slides'          => is_array($s['header_slider'] ?? null) ? $s['header_slider'] : self::header_slider_default_slides(),
 			'show_on_pages'   => $show_on,
 			'show_type'       => $show_type,
-			'nav_color'       => sanitize_hex_color((string) ($s['header_slider_nav_color'] ?? '')) ?: '',
+			'nav_color'       => \AKSRT\Core\Color::sanitize((string) ($s['header_slider_nav_color'] ?? '')) ?: '',
 			'slider_config'   => $slider_option,
 			'search_show'     => self::sanitize_device_visibility($s['header_slider_search_s'] ?? ['pc_s', 'm_s']),
 			'search_config'   => $search_option,

src/Settings/FacadeBulk.php

@@ -18,9 +18,9 @@ trait FacadeBulk {
 
         return [
 			'custom'       => !empty($s['header_theme_custom']),
-			'bg_custom'    => sanitize_hex_color((string) ($s['header_theme_bg_custom'] ?? '')) ?: '',
+			'bg_custom'    => \AKSRT\Core\Color::sanitize((string) ($s['header_theme_bg_custom'] ?? '')) ?: '',
 			'bg'           => self::normalize_palette_hex((string) ($s['header_theme_bg'] ?? '')),
-			'color_custom' => sanitize_hex_color((string) ($s['header_theme_color_custom'] ?? '')) ?: '',
+			'color_custom' => \AKSRT\Core\Color::sanitize((string) ($s['header_theme_color_custom'] ?? '')) ?: '',
         ];
     }
 

src/Settings/FloatButtons.php

@@ -218,25 +218,8 @@ class FloatButtons {
 	private static function sanitize_color_group($group): array {
 		$group = is_array($group) ? $group : [];
 		return [
-			'color' => self::sanitize_color((string) ($group['color'] ?? '')),
-			'bg'    => self::sanitize_color((string) ($group['bg'] ?? '')),
+			'color' => \AKSRT\Core\Color::sanitize($group['color'] ?? '', true),
+			'bg'    => \AKSRT\Core\Color::sanitize($group['bg'] ?? '', true),
 		];
 	}
-
-	/**
-	 * 允许 #hex（3/4/6/8 位）与 rgb()/rgba()。
-	 */
-	public static function sanitize_color(string $value): string {
-		$value = trim($value);
-		if ($value === '') {
-			return '';
-		}
-		if (preg_match('/^#(?:[0-9a-fA-F]{3,4}|[0-9a-fA-F]{6}|[0-9a-fA-F]{8})$/', $value)) {
-			return $value;
-		}
-		if (preg_match('/^rgba?\(\s*\d{1,3}\s*,\s*\d{1,3}\s*,\s*\d{1,3}\s*(?:,\s*(?:0|1|0?\.\d+)\s*)?\)$/', $value)) {
-			return $value;
-		}
-		return '';
-	}
 }

src/Settings/HomeCms.php

@@ -61,9 +61,9 @@ class HomeCms {
 		$s = self::get_footer_settings();
         return [
             'custom'       => !empty($s['footer_theme_custom']),
-            'bg_custom'    => sanitize_hex_color((string) ($s['footer_theme_bg_custom'] ?? '')) ?: '',
+            'bg_custom'    => \AKSRT\Core\Color::sanitize((string) ($s['footer_theme_bg_custom'] ?? '')) ?: '',
 			'bg'           => self::normalize_palette_hex((string) ($s['footer_theme_bg'] ?? '')),
-            'color_custom' => sanitize_hex_color((string) ($s['footer_theme_color_custom'] ?? '')) ?: '',
+            'color_custom' => \AKSRT\Core\Color::sanitize((string) ($s['footer_theme_color_custom'] ?? '')) ?: '',
         ];
     }
 

src/Settings/ThemeSearch.php

@@ -388,12 +388,10 @@ class ThemeSearch {
         return '';
     }
 
-    private const HEX_PATTERN = '/^#([0-9a-fA-F]{3}|[0-9a-fA-F]{6})$/';
-
     /** 全局主题色：theme_skin_custom 优先，清空时使用 theme_skin 预置色（对齐参考主题 zib_head_css）。 */
     public static function theme_color(): string {
-        $custom = trim((string) Settings::get_value('theme_skin_custom', ''));
-        if (preg_match(self::HEX_PATTERN, $custom)) {
+        $custom = \AKSRT\Core\Color::sanitize(Settings::get_value('theme_skin_custom', ''));
+        if ($custom !== '') {
             return $custom;
         }
         $skin = ltrim(trim((string) Settings::get_value('theme_skin', 'f04494')), '#');
@@ -402,8 +400,7 @@ class ThemeSearch {
 
     /** 夜间模式主题色；未设置返回空串，夜间沿用全局主题色。 */
     public static function dark_theme_color(): string {
-        $color = trim((string) Settings::get_value('dark_theme_skin_custom', ''));
-        return preg_match(self::HEX_PATTERN, $color) ? $color : '';
+        return \AKSRT\Core\Color::sanitize(Settings::get_value('dark_theme_skin_custom', ''));
     }
 
     public static function get_theme_mode_button_positions(): array {
@@ -429,8 +426,7 @@ class ThemeSearch {
         if (!is_array($bg)) {
             return '';
         }
-        $color = trim((string) ($bg['color'] ?? ''));
-        $color = preg_match(self::HEX_PATTERN, $color) ? $color : '';
+        $color = \AKSRT\Core\Color::sanitize($bg['color'] ?? '');
         $image = esc_url_raw(trim((string) ($bg['image'] ?? '')));
         if ($color === '' && $image === '') {
             return '';