Add complete custom fields implementation and entry editing

- Add custom field CRUD in admin UI (create, read, update, delete)
- Display custom fields on frontend form with proper field types
- Save custom field values on form submission
- Display custom field columns in entries table (admin and public)
- Include custom field values in all export formats (CSV, PairGoTh, OpenGotha, McMahon)
- Add Edit button and form for entries
- Update entry handler to support editing with custom field values
- Add success/error notices for all admin actions

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

go-form-plugin/templates/table.php

@@ -8,6 +8,14 @@
       <th>Rank</th>
       <th>EGD Number</th>
       <th>Date Added</th>
+      <?php
+      // Add custom field columns
+      foreach ($custom_fields as $field):
+        if ($field->is_public || $show_admin):
+          echo '<th>' . esc_html($field->field_name) . '</th>';
+        endif;
+      endforeach;
+      ?>
       <?php if ($show_admin): ?>
         <th>Rating</th>
         <th>Action</th>
@@ -26,11 +34,27 @@
         <td> <?= esc_html($ranks[$e->rank]) ?> </td>
         <td> <?= esc_html($e->egd_number) ?> </td>
         <td> <?= esc_html($e->created_at) ?> </td>
+        <?php
+        // Display custom field values
+        foreach ($custom_fields as $field):
+          if ($field->is_public || $show_admin):
+            echo '<td>';
+            $value = go_form_get_custom_value($e->id, $field->id);
+            if ($field->field_type === 'checkbox') {
+              echo $value ? 'Yes' : 'No';
+            } else {
+              echo esc_html($value);
+            }
+            echo '</td>';
+          endif;
+        endforeach;
+        ?>
         
         <?php if ($show_admin): ?>
 
           <td> <?= esc_html($e->rating) ?> </td>
           <td>
+            <a href="<?= add_query_arg(array('page' => 'go-form-settings', 'form_id' => $form_id ?? 0, 'edit_entry' => $e->id), admin_url('admin.php')) ?>" class="button button-small">Edit</a>
             <?php action_button('go_form_delete_entry', 'Delete', 'Delete this entry?', $e->id); ?>
           </td>