fix: Remove duplicate withCommand() call in Container.php

The previous implementation called withCommand() twice:
- Once when creating the container
- Again after adding signing key parameters

This caused issues in CI environments. The fix builds the complete
command array first, then calls withCommand() only once at the end.

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

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

Author: goloroden

src/Container.php

@@ -59,8 +59,7 @@ public function start(): void
         ];
 
         $container = (new GenericContainer("{$this->imageName}:{$this->imageTag}"))
-            ->withExposedPorts($this->internalPort)
-            ->withCommand($command);
+            ->withExposedPorts($this->internalPort);
 
         if ($this->signingKey instanceof SigningKey) {
             // Create a temporary file with the signing key
@@ -70,15 +69,17 @@ public function start(): void
             }
             file_put_contents($tempFile, $this->signingKey->privateKeyPem);
 
-            // Mount the temp file into the container
+            // Add signing key parameters to command
             $command[] = '--signing-key-file';
             $command[] = '/tmp/signing-key.pem';
-            $container = $container
-                ->withCommand($command)
-                ->withMount($tempFile, '/tmp/signing-key.pem');
+
+            // Mount the temp file into the container
+            $container = $container->withMount($tempFile, '/tmp/signing-key.pem');
         }
 
-        $container = $container->withWait((new WaitForHttp($this->internalPort, 20000))->withPath('/api/v1/ping'));
+        $container = $container
+            ->withCommand($command)
+            ->withWait((new WaitForHttp($this->internalPort, 20000))->withPath('/api/v1/ping'));
 
         try {
             $this->container = $container->start();