feat: Add product price comparison table

- Add "Load Product Comparison" button in admin
- Display WooCommerce products with local price (sale/regular)
- Show Google Merchant Center price for each product
- Show match type (offerId vs gtin) and match status
- Helps debug product matching issues
- Limited to 50 in-stock products for performance

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

assets/js/admin.js

@@ -20,6 +20,7 @@
 			$('#informatiq-sp-manual-sync').on('click', this.handleManualSync);
 			$('#informatiq-sp-test-connection').on('click', this.handleTestConnection);
 			$('#informatiq-sp-revoke-auth').on('click', this.handleRevokeAuth);
+			$('#informatiq-sp-compare-products').on('click', this.handleCompareProducts);
 		},
 
 		/**
@@ -179,6 +180,82 @@
 					$button.prop('disabled', false).text('Revoke Authorization');
 				}
 			});
+		},
+
+		/**
+		 * Handle compare products button click
+		 */
+		handleCompareProducts: function(e) {
+			e.preventDefault();
+
+			var $button = $(this);
+			var $spinner = $button.next('.spinner');
+			var $results = $('#informatiq-sp-comparison-results');
+			var $tbody = $('#informatiq-sp-comparison-tbody');
+
+			// Disable button and show spinner
+			$button.prop('disabled', true);
+			$spinner.addClass('is-active');
+
+			// Make AJAX request
+			$.ajax({
+				url: informatiqSP.ajaxUrl,
+				type: 'POST',
+				data: {
+					action: 'informatiq_sp_compare_products',
+					nonce: informatiqSP.nonce
+				},
+				success: function(response) {
+					if (response.success) {
+						var data = response.data;
+						var html = '';
+
+						if (data.products.length === 0) {
+							html = '<tr><td colspan="6">No in-stock products with SKU found.</td></tr>';
+						} else {
+							$.each(data.products, function(i, product) {
+								var localPrice = product.local_price ? data.currency + parseFloat(product.local_price).toFixed(2) : '-';
+								var googlePrice = product.google_price ? data.currency + parseFloat(product.google_price).toFixed(2) : '-';
+								var priceLabel = product.price_type === 'sale' ? ' <small>(sale)</small>' : ' <small>(regular)</small>';
+								var matchLabel = product.match_type ? product.match_type : '-';
+								var statusClass = product.found ? 'color: #00a32a;' : 'color: #d63638;';
+								var statusText = product.found ? 'Found' : 'Not Found';
+
+								if (product.found && product.google_offer) {
+									matchLabel += ' <small>(' + product.google_offer + ')</small>';
+								}
+
+								html += '<tr>';
+								html += '<td><a href="post.php?post=' + product.id + '&action=edit">' + product.name + '</a></td>';
+								html += '<td><code>' + product.sku + '</code></td>';
+								html += '<td>' + localPrice + priceLabel + '</td>';
+								html += '<td>' + googlePrice + '</td>';
+								html += '<td>' + matchLabel + '</td>';
+								html += '<td style="' + statusClass + '"><strong>' + statusText + '</strong></td>';
+								html += '</tr>';
+							});
+						}
+
+						$tbody.html(html);
+						$results.show();
+
+						// Show summary
+						var summary = 'Showing ' + data.products.length + ' WooCommerce products. ';
+						summary += data.google_count + ' products found in Google Merchant Center.';
+						$button.after('<p class="description" style="margin-top: 10px;">' + summary + '</p>');
+
+					} else {
+						alert('Error: ' + (response.data.message || 'Unknown error'));
+					}
+				},
+				error: function(jqXHR, textStatus, errorThrown) {
+					alert('Error: ' + errorThrown);
+				},
+				complete: function() {
+					$button.prop('disabled', false);
+					$spinner.removeClass('is-active');
+				}
+			});
 		}
 	};