fix: Fix environment variables not being captured correctly in PHP-FPM

- Fix priority order in loadSystemEnvironment() to check  and  first
- Add dynamic fallback in Environment::get() to handle variables set after initialization
- Ensure all environment variables are captured during bootstrap, including those set dynamically by PHP-FPM/FastCGI

Fixes issue where environment variables like RAPIDMAIL_USERNAME and RAPIDMAIL_PASSWORD were missing during bootstrap but available later in request processing.

src/Framework/Config/Environment.php

@@ -23,7 +23,7 @@ final readonly class Environment
     {
         $key = $this->keyToString($key);
 
-        // 1. Check if direct env var exists
+        // 1. Check if direct env var exists in internal array
         if (isset($this->variables[$key])) {
             return $this->variables[$key];
         }
@@ -34,10 +34,45 @@ final readonly class Environment
             return $secretValue;
         }
 
-        // 3. Return default
+        // 3. Fallback: Check system environment dynamically
+        // This handles cases where environment variables are set after Environment initialization
+        // (common in PHP-FPM where vars may be set during request processing)
+        $systemValue = $this->getFromSystemEnvironment($key);
+        if ($systemValue !== null) {
+            return $systemValue;
+        }
+
+        // 4. Return default
         return $default;
     }
 
+    /**
+     * Get variable from system environment as fallback
+     * 
+     * This ensures we can access environment variables that were set
+     * after Environment initialization (e.g., by PHP-FPM/FastCGI)
+     */
+    private function getFromSystemEnvironment(string $key): ?string
+    {
+        // Priority: $_ENV > $_SERVER > getenv()
+        // $_ENV and $_SERVER may contain dynamically set vars in PHP-FPM
+        
+        if (isset($_ENV[$key]) && is_string($_ENV[$key])) {
+            return $_ENV[$key];
+        }
+
+        if (isset($_SERVER[$key]) && is_string($_SERVER[$key]) && !str_starts_with($key, 'HTTP_')) {
+            return $_SERVER[$key];
+        }
+
+        $value = getenv($key);
+        if ($value !== false && is_string($value)) {
+            return $value;
+        }
+
+        return null;
+    }
+
     public function getRequired(EnvKey|string $key): mixed
     {
         $key = $this->keyToString($key);
@@ -115,11 +150,7 @@ final readonly class Environment
      */
     public function all(): array
     {
-        return array_merge(
-            #$_ENV,
-            #$_SERVER,
-            $this->variables
-        );
+        return $this->variables;
     }
 
     /**