fix: Modal initial values + sticky footer + HTML descriptions

✅ Issue 1: Modal Not Showing Current Values (FIXED!)
Problem: Opening modal showed defaults, not current saved values
Root Cause: Backend only sent field.default, not current value
Solution:
- Backend: Added field.value with current saved value
- normalize_field() now includes: value: $current_settings[$key]
- Frontend: Use field.value ?? field.default for initial data
- GenericGatewayForm initializes with current values

Result: ✅ Modal now shows "BNI Virtual Account 2" not "BNI Virtual Account"

✅ Issue 2: Sticky Modal Footer (FIXED!)
Problem: Footer scrolls away with long forms
Solution:
- Restructured modal: header + scrollable body + sticky footer
- DialogContent: flex flex-col with overflow on body only
- Footer: sticky bottom-0 with border-t
- Save button triggers form.requestSubmit()

Result: ✅ Cancel, View in WooCommerce, Save always visible

✅ Issue 3: HTML in Descriptions (FIXED!)
Problem: TriPay icon shows as raw HTML string
Solution:
- Changed: {field.description}
- To: dangerouslySetInnerHTML={{ __html: field.description }}
- Respects vendor creativity (images, formatting, links)

Result: ✅ TriPay icon image renders properly

📋 Technical Details:

Backend Changes (PaymentGatewaysProvider.php):
- get_gateway_settings() passes $current_settings to extractors
- normalize_field() adds 'value' => $current_settings[$key]
- All fields now have both default and current value

Frontend Changes:
- GatewayField interface: Added value?: string | boolean
- GenericGatewayForm: Initialize with field.value
- Modal structure: Header + Body (scroll) + Footer (sticky)
- Descriptions: Render as HTML with dangerouslySetInnerHTML

Files Modified:
- PaymentGatewaysProvider.php: Add current values to fields
- Payments.tsx: Restructure modal layout + add value to interface
- GenericGatewayForm.tsx: Use field.value + sticky footer + HTML descriptions

🎯 Result:
✅ Modal shows current saved values
✅ Footer always visible (no scrolling)
✅ Vendor HTML/images render properly

includes/Compat/PaymentGatewaysProvider.php

@@ -194,11 +194,12 @@ class PaymentGatewaysProvider {
      */
     private static function get_gateway_settings(WC_Payment_Gateway $gateway): array {
         $form_fields = $gateway->get_form_fields();
+        $current_settings = $gateway->settings;  // Get current saved values
         
         return [
-            'basic' => self::extract_basic_fields($form_fields),
-            'api' => self::extract_api_fields($form_fields),
-            'advanced' => self::extract_advanced_fields($form_fields),
+            'basic' => self::extract_basic_fields($form_fields, $current_settings),
+            'api' => self::extract_api_fields($form_fields, $current_settings),
+            'advanced' => self::extract_advanced_fields($form_fields, $current_settings),
         ];
     }
     
@@ -208,9 +209,9 @@ class PaymentGatewaysProvider {
      * @param array $form_fields All form fields
      * @return array Basic fields
      */
-    private static function extract_basic_fields(array $form_fields): array {
+    private static function extract_basic_fields(array $form_fields, array $current_settings): array {
         $basic_keys = ['enabled', 'title', 'description', 'instructions'];
-        return self::filter_fields($form_fields, $basic_keys);
+        return self::filter_fields($form_fields, $basic_keys, $current_settings);
     }
     
     /**
@@ -219,14 +220,14 @@ class PaymentGatewaysProvider {
      * @param array $form_fields All form fields
      * @return array API fields
      */
-    private static function extract_api_fields(array $form_fields): array {
+    private static function extract_api_fields(array $form_fields, array $current_settings): array {
         $api_patterns = ['key', 'secret', 'token', 'api', 'client', 'merchant', 'account'];
         $api_fields = [];
         
         foreach ($form_fields as $key => $field) {
             foreach ($api_patterns as $pattern) {
                 if (stripos($key, $pattern) !== false) {
-                    $api_fields[$key] = self::normalize_field($key, $field);
+                    $api_fields[$key] = self::normalize_field($key, $field, $current_settings);
                     break;
                 }
             }
@@ -241,7 +242,7 @@ class PaymentGatewaysProvider {
      * @param array $form_fields All form fields
      * @return array Advanced fields
      */
-    private static function extract_advanced_fields(array $form_fields): array {
+    private static function extract_advanced_fields(array $form_fields, array $current_settings): array {
         $basic_keys = ['enabled', 'title', 'description', 'instructions'];
         $advanced_fields = [];
         
@@ -262,7 +263,7 @@ class PaymentGatewaysProvider {
             }
             
             if (!$is_api) {
-                $advanced_fields[$key] = self::normalize_field($key, $field);
+                $advanced_fields[$key] = self::normalize_field($key, $field, $current_settings);
             }
         }
         
@@ -276,12 +277,12 @@ class PaymentGatewaysProvider {
      * @param array $keys Keys to extract
      * @return array Filtered fields
      */
-    private static function filter_fields(array $form_fields, array $keys): array {
+    private static function filter_fields(array $form_fields, array $keys, array $current_settings): array {
         $filtered = [];
         
         foreach ($keys as $key) {
             if (isset($form_fields[$key])) {
-                $filtered[$key] = self::normalize_field($key, $form_fields[$key]);
+                $filtered[$key] = self::normalize_field($key, $form_fields[$key], $current_settings);
             }
         }
         
@@ -295,13 +296,17 @@ class PaymentGatewaysProvider {
      * @param array $field Field data
      * @return array Normalized field
      */
-    private static function normalize_field(string $key, array $field): array {
+    private static function normalize_field(string $key, array $field, array $current_settings): array {
+        // Use current value if available, otherwise use default
+        $current_value = $current_settings[$key] ?? $field['default'] ?? '';
+        
         return [
             'id' => $key,
             'type' => $field['type'] ?? 'text',
             'title' => $field['title'] ?? '',
             'description' => $field['description'] ?? '',
             'default' => $field['default'] ?? '',
+            'value' => $current_value,  // Add current value!
             'placeholder' => $field['placeholder'] ?? '',
             'required' => !empty($field['required']),
             'options' => $field['options'] ?? null,