feat: EXT:staticfilecache serves cached pages without PHP again, as on TYPO3 10

Every page view goes through TYPO3 13 since the switch; staticfilecache
15.2 writes a gzip copy of each cacheable page, and the TYPO3 10 rewrite
rules in public/.htaccess let Apache deliver it directly (GET, no query
string, no backend login). Pages answer in about 2 ms instead of
0.5-4 s; static and dynamic output are identical for a sample of 22
sitemap URLs.

A flush of the pages cache group (travel data and snow report imports,
"clear frontend caches", deploys) removes the files; a page's own cache
lifetime still applies through the generated per-page .htaccess.

X-SFC-Tags is not passed on: with every record of a page as a tag it
reaches 100+ KB, more than Apache accepts from PHP-FPM, and it would
expose internal record ids. Debug headers stay off for the same reason.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

config/system/settings.php

@@ -97,6 +97,44 @@ return [
         'scheduler' => [
             'maxLifetime' => '1440',
         ],
+        'staticfilecache' => [
+            'backendDisplayMode' => 'both',
+            'boostMode' => '0',
+            'clearCacheForAllDomains' => '1',
+            'cspGenerationOverride' => '0',
+            'debugHeaders' => '0',
+            'disableInDevelopment' => '0',
+            'enableGeneratorBrotli' => '0',
+            'enableGeneratorGzip' => '1',
+            'enableGeneratorPhp' => '0',
+            'enableGeneratorPlain' => '0',
+            'hashUriInCache' => '0',
+            'headerSizeBuffer' => '1.5',
+            'htaccessTemplateName' => 'EXT:staticfilecache/Resources/Private/Templates/Htaccess.html',
+            'inlineAssetsFileSize' => '50000',
+            'inlineScriptMinify' => '0',
+            'inlineServiceFavIcon' => '0',
+            'inlineServiceScripts' => '0',
+            'inlineServiceStyles' => '0',
+            'inlineStyleAssets' => 'ico,png,woff2',
+            'inlineStyleMinify' => '0',
+            'largeIdentifierInCacheTable' => '0',
+            'maxHeaderSize' => '8192',
+            'overrideCacheDirectory' => '',
+            'overrideClientUserAgent' => '',
+            'phpTemplateName' => 'EXT:staticfilecache/Resources/Private/Templates/Php.html',
+            'rawurldecodeCacheFileName' => '0',
+            'renameTablesToOtherPrefix' => '0',
+            'sendCacheControlHeaderRedirectAfterCacheTimeout' => '1',
+            'sendHttp2PushEnable' => '0',
+            'sendHttp2PushFileExtensions' => 'css,js',
+            'sendHttp2PushFileLimit' => '10',
+            'sendHttp2PushLimitToArea' => '',
+            'useFallbackMiddleware' => '1',
+            'useReverseUriLengthInPriority' => '1',
+            'validFallbackHeaders' => 'Content-Type,Content-Language,Content-Security-Policy,Link',
+            'validHtaccessHeaders' => 'Content-Type,Content-Language,Content-Security-Policy,Link',
+        ],
     ],
     'FE' => [
         'cacheHash' => [