fix(footer): align template_1 shell with Zibll 1:1

Rewrite footer markup to zib_footer_con contract: single adaptive logo
(white-src/dark-src), fcode-links HTML primary, float third column,
hidden-xs, toggle-radius contacts, miniimg structure, customize-first
footer-conter. Restyle zibll-shell CSS and drop conflicting site-footer
BEM padding so filled footer data matches Zibll layout.

inc/helpers/aksrt-template-tags.php

@@ -474,6 +474,45 @@ function aksrt_get_site_logo_width(): int {
 }
 endif;
 
+if (!function_exists('aksrt_get_adaptive_theme_img')):
+/**
+ * Build a single light/dark adaptive image (Zibll white-src/dark-src contract).
+ *
+ * theme.js syncThemeImages() swaps src via white-src / dark-src attributes.
+ *
+ * @param string $white_src Light mode image URL.
+ * @param string $dark_src  Dark mode image URL.
+ * @param string $alt       Alt text.
+ * @param string $more      Extra attributes (already escaped by caller if needed).
+ * @return string
+ */
+function aksrt_get_adaptive_theme_img(string $white_src = '', string $dark_src = '', string $alt = '', string $more = ''): string {
+    $white_src = trim($white_src);
+    $dark_src  = trim($dark_src);
+
+    if ($white_src === '' && $dark_src === '') {
+        return '';
+    }
+    if ($dark_src === '') {
+        $dark_src = $white_src;
+    }
+    if ($white_src === '') {
+        $white_src = $dark_src;
+    }
+    if ($alt === '') {
+        $alt = get_bloginfo('name');
+    }
+
+    $is_dark = false;
+    if (class_exists('AKSRT_Settings') && method_exists('AKSRT_Settings', 'initial_theme_mode')) {
+        $is_dark = AKSRT_Settings::initial_theme_mode() === 'dark';
+    }
+    $this_src = $is_dark ? $dark_src : $white_src;
+
+    return '<img src="' . esc_url($this_src) . '" white-src="' . esc_url($white_src) . '" dark-src="' . esc_url($dark_src) . '" alt="' . esc_attr($alt) . '"' . ($more !== '' ? ' ' . $more : '') . ' loading="lazy">';
+}
+endif;
+
 if (!function_exists('aksrt_get_search_placeholder')):
 /**
  * 获取搜索占位文案