Add plugin structure, lazy load feature, and basic admin settings

includes/speed-functions.php

@@ -0,0 +1,18 @@
+<?php
+/**
+ * Speed optimization functions
+ */
+
+function wpa_superstar_lazy_load_images( $content ) {
+    if ( is_admin() || ! $content || ! get_option( 'wpa_superstar_lazy_load', 1 ) ) {
+        return $content;
+    }
+    $content = preg_replace(
+        '/(<img[^>]+)\/?>/i',
+        '$1 loading="lazy" />',
+        $content
+    );
+    return $content;
+}
+add_filter( 'the_content', 'wpa_superstar_lazy_load_images' );
+add_filter( 'wp_get_attachment_image', 'wpa_superstar_lazy_load_images' );