fix(css-manager): remove debug logging, CSS injection confirmed working

CSS injection is working correctly in production:
- roi-custom-deferred-css appears in page output
- 2 snippets with 24KB of CSS being injected

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

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

Public/CustomCSSManager/Infrastructure/Services/CustomCSSInjector.php

@@ -35,21 +35,14 @@ final class CustomCSSInjector
      */
     public function injectCriticalCSS(): void
     {
-        error_log('ROI CustomCSS: injectCriticalCSS CALLED');
-
         $pageType = $this->getCurrentPageType();
-        error_log('ROI CustomCSS: pageType=' . $pageType);
-
         $snippets = $this->getCriticalUseCase->execute($pageType);
-        error_log('ROI CustomCSS: critical snippets count=' . count($snippets));
 
         if (empty($snippets)) {
-            error_log('ROI CustomCSS: NO critical snippets, returning');
             return;
         }
 
         $css = $this->combineSnippets($snippets);
-        error_log('ROI CustomCSS: critical CSS length=' . strlen($css));
 
         if (!empty($css)) {
             printf(
@@ -64,21 +57,14 @@ final class CustomCSSInjector
      */
     public function injectDeferredCSS(): void
     {
-        error_log('ROI CustomCSS: injectDeferredCSS CALLED');
-
         $pageType = $this->getCurrentPageType();
-        error_log('ROI CustomCSS: deferred pageType=' . $pageType);
-
         $snippets = $this->getDeferredUseCase->execute($pageType);
-        error_log('ROI CustomCSS: deferred snippets count=' . count($snippets));
 
         if (empty($snippets)) {
-            error_log('ROI CustomCSS: NO deferred snippets, returning');
             return;
         }
 
         $css = $this->combineSnippets($snippets);
-        error_log('ROI CustomCSS: deferred CSS length=' . strlen($css));
 
         if (!empty($css)) {
             printf(