feat: caching, optimization, legal pages & footer

- WP Super Cache enabled (PHP mode, gzip, Nginx compatible)
- Autoptimize: CSS/HTML minification + deferred JS + Google Fonts optimization
- Cookie Notice: GDPR/LOPD banner styled with brand colors (navy/burgundy/gold)
- Legal pages: Aviso Legal, Política de Privacidad, Política de Cookies (ES)
- MU-plugin: custom footer with legal links + Cloud Host credit
- Footer: copyright, legal nav, Hosted & Maintained by Cloud Host (cloudhost.es)
- Security: X-Frame-Options, X-Content-Type, Referrer-Policy headers
- Security: XML-RPC disabled, REST user enumeration blocked
- Performance: emoji scripts removed, post revisions limited to 3

wp-content/plugins/autoptimize/classes/critcss-inc/admin_settings_explain.php

@@ -0,0 +1,57 @@
+<?php
+/**
+ * Explain what CCSS is (visible if no API key is stored).
+ */
+
+/**
+ * Actual function that explains.
+ */
+function ao_ccss_render_explain() {
+    ?>
+    <style>
+        .ao_settings_div {background: white;border: 1px solid #ccc;padding: 1px 15px;margin: 15px 10px 10px 0;}
+        .ao_settings_div .form-table th {font-weight: normal;}
+    </style>
+    <script>document.title = "Autoptimize: <?php esc_html_e( 'Critical CSS', 'autoptimize' ); ?> " + document.title;</script>
+    <ul id="explain-panel">
+        <div class="ao_settings_div">
+            <?php
+            $ccss_explanation = '';
+
+            if ( apply_filters( 'autoptimize_filter_ccss_rules_without_api', true ) ) {
+                $_transient    = 'ao3_ccss_explain';
+                $_explain_html = 'https://misc.optimizingmatters.com/autoptimize_ccss_explain_ao30_i18n.html?ao_ver=';
+            } else {
+                $_transient    = 'ao_ccss_explain';
+                $_explain_html = 'https://misc.optimizingmatters.com/autoptimize_ccss_explain_i18n.html?ao_ver=';
+            }
+
+            // get the HTML with the explanation of what critical CSS is.
+            if ( apply_filters( 'autoptimize_settingsscreen_remotehttp', true ) ) {
+                $ccss_explanation = get_transient( $_transient );
+                if ( empty( $ccss_explanation ) ) {
+                    $ccss_expl_resp = wp_remote_get( $_explain_html . AUTOPTIMIZE_PLUGIN_VERSION );
+                    if ( ! is_wp_error( $ccss_expl_resp ) ) {
+                        if ( '200' == wp_remote_retrieve_response_code( $ccss_expl_resp ) ) {
+                            $ccss_explanation = wp_kses_post( wp_remote_retrieve_body( $ccss_expl_resp ) );
+                            set_transient( $_transient, $ccss_explanation, WEEK_IN_SECONDS );
+                        }
+                    }
+                }
+            }
+
+            // placeholder text in case HTML is empty.
+            if ( empty( $ccss_explanation ) ) {
+                $ccss_explanation = sprintf( esc_html__( '%1$sFix render-blocking CSS!%2$s%3$sSignificantly improve your first-paint times by making CSS non-render-blocking.%4$s%3$sThe %5$snext step is to sign up at %7$shttps://criticalcss.com%8$s%6$s (this is a premium service, priced 2 GBP/month for membership and 5 GBP/month per domain) %5$sand get the API key%6$s, which you can copy from %7$sthe API-keys page%8$s and paste below.%4$s%3$sIf you have any questions or need support, head on over to %9$sour support forum%10$s and we\'ll help you get up and running in no time!%4$s', 'autoptimize' ), '<h2>', '</h2>', '<p>', '</p>', '<strong>', '</strong>', '<a href="https://criticalcss.com/?aff=1" target="_blank">', '</a>', '<a href="https://wordpress.org/support/plugin/autoptimize" target="_blank">', '</a>' );
+            } else {
+                // we were able to fetch the explenation, so add the JS to show correct language.
+                $ccss_explanation .= "<script>jQuery('.ao_i18n').hide();d=document;lang=d.getElementsByTagName('html')[0].getAttribute('lang').substring(0,2);if(d.getElementById(lang)!= null){jQuery('#'+lang).show();}else{jQuery('#default').show();}</script>";
+            }
+
+            // and echo it.
+            echo $ccss_explanation;
+            ?>
+        </div>
+        </ul>
+    <?php
+}