Add WebP thumbnail endpoint for MLS property images

- Create MLS_Image_Endpoint class with on-demand thumbnail generation
- Use ImageMagick to convert images to WebP format
- Thumbnail sizes: 800px (thumb) and 1800px (full), maintain aspect ratio
- Only downsize images, never upsize
- Cache thumbnails in wp-content/uploads/mls-thumbnails/
- Add mls_get_image_url() helper function (1-based index)
- Update property cards to display thumbnail as background-cover image
- Long cache headers (1 year) with ETag support

URL format: /mls-image/{listing_key}/{index}/{size}/

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

wp-content/plugins/mls-by-hansonxyz/mls-by-hansonxyz.php

@@ -52,6 +52,7 @@ final class MLS_Plugin {
     private $api_client;
     private $sync_engine;
     private $media_handler;
+    private $image_endpoint;
     private $query;
 
     /**
@@ -84,6 +85,7 @@ final class MLS_Plugin {
         require_once MLS_PLUGIN_DIR . 'includes/class-mls-api-client.php';
         require_once MLS_PLUGIN_DIR . 'includes/class-mls-sync-engine.php';
         require_once MLS_PLUGIN_DIR . 'includes/class-mls-media-handler.php';
+        require_once MLS_PLUGIN_DIR . 'includes/class-mls-image-endpoint.php';
         require_once MLS_PLUGIN_DIR . 'includes/class-mls-query.php';
 
         // Activation/Deactivation
@@ -126,6 +128,8 @@ final class MLS_Plugin {
         $this->rate_limiter = new MLS_Rate_Limiter($this->db);
         $this->api_client = new MLS_API_Client($this->options, $this->rate_limiter, $this->logger);
         $this->media_handler = new MLS_Media_Handler($this->db, $this->logger);
+        $this->image_endpoint = new MLS_Image_Endpoint($this->media_handler, $this->logger);
+        $this->image_endpoint->init();
         $this->sync_engine = new MLS_Sync_Engine(
             $this->db,
             $this->api_client,
@@ -206,6 +210,13 @@ final class MLS_Plugin {
         return $this->media_handler;
     }
 
+    /**
+     * Get Image Endpoint instance
+     */
+    public function get_image_endpoint() {
+        return $this->image_endpoint;
+    }
+
     /**
      * Get Query instance
      */
@@ -359,3 +370,21 @@ function mls_get_cache_stats() {
     }
     return $plugin->get_media_handler()->get_cache_stats();
 }
+
+/**
+ * Get WebP thumbnail URL for a listing image
+ *
+ * Returns a URL to the WebP thumbnail endpoint which will:
+ * - Fetch the image from MLS Grid if not cached
+ * - Convert to WebP format using ImageMagick
+ * - Resize to requested dimension (800px thumb or 1800px full)
+ * - Cache the result for future requests
+ *
+ * @param string $listing_key The listing key
+ * @param int $index Image index (1-based, default: 1 for primary image)
+ * @param string $size 'thumb' (800px) or 'full' (1800px), default: 'thumb'
+ * @return string Image URL
+ */
+function mls_get_image_url($listing_key, $index = 1, $size = 'thumb') {
+    return MLS_Image_Endpoint::get_url($listing_key, $index, $size);
+}