php-fpm: refactor with deterministic config files & improved debug

shared/php-fpm/force-debug.php

@@ -1,14 +1,23 @@
 <?php
 // force-debug.php
-// This script is prepended to all PHP requests to force error reporting.
+// Optional debug bootstrap that can be toggled with FORCE_DEBUG_ERRORS=1.
+
+$forceDebug = getenv('FORCE_DEBUG_ERRORS');
+if ($forceDebug === false) {
+	return;
+}
+
+$normalized = strtolower(trim($forceDebug));
+$enabled = in_array($normalized, ['1', 'true', 'yes', 'on'], true);
+
+if (!$enabled) {
+	return;
+}
 
-// Set error reporting to the highest level.
 error_reporting(E_ALL);
-
-// Ensure errors are displayed directly in the browser.
-// This overrides any ini_set('display_errors', 'Off') in the application.
 ini_set('display_errors', '1');
-
-// Also ensure errors are logged.
+ini_set('display_startup_errors', '1');
 ini_set('log_errors', '1');
-?>
+ini_set('error_log', '/proc/self/fd/2');
+
+error_log('[force-debug] Verbose error reporting enabled via FORCE_DEBUG_ERRORS');