refactor(astrolabe): add PHP property types to fix Psalm errors

Add explicit property type declarations to IdpTokenRefresher,
CredentialsController, OAuthController, and McpServerClient classes.
This improves type safety and allows Psalm to properly infer types,
eliminating MissingPropertyType and many MixedMethodCall errors.

Also adds IClient import where needed and validates getSystemValue
returns to ensure string types before use.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

third_party/astrolabe/lib/Controller/CredentialsController.php

@@ -23,13 +23,13 @@ use Psr\Log\LoggerInterface;
  * Handles storing and validating app passwords for multi-user BasicAuth mode.
  */
 class CredentialsController extends Controller {
-	private $tokenStorage;
-	private $userSession;
-	private $logger;
-	private $config;
-	private $client;
-	private $httpClientService;
-	private $urlGenerator;
+	private McpTokenStorage $tokenStorage;
+	private IUserSession $userSession;
+	private LoggerInterface $logger;
+	private IConfig $config;
+	private McpServerClient $client;
+	private IClientService $httpClientService;
+	private IURLGenerator $urlGenerator;
 
 	public function __construct(
 		string $appName,