diff --git a/examples/config/neuron.yaml b/examples/config/neuron.yaml
index 154004f..b6fc488 100644
--- a/examples/config/neuron.yaml
+++ b/examples/config/neuron.yaml
@@ -55,3 +55,18 @@ member:
   # Email verification token expiration time (in minutes)
   # Tokens older than this will be considered invalid
   verification_token_expiration_minutes: 60
+
+# Exception Handling Configuration
+exceptions:
+  # Exceptions that should pass through to application-level handlers
+  # instead of being caught by the framework's error handler.
+  # This is useful for custom error pages or specific exception handling logic.
+  passthrough:
+    # CMS-specific exceptions that require special handling (redirects, specific error pages)
+    - Neuron\Cms\Exceptions\UnauthenticatedException
+    - Neuron\Cms\Exceptions\EmailVerificationRequiredException
+    - Neuron\Cms\Exceptions\CsrfValidationException
+    # Additional exceptions can be added as needed
+    # - RuntimeException
+    # - LogicException
+    # - InvalidArgumentException
diff --git a/resources/config/neuron.yaml b/resources/config/neuron.yaml
index e8a072c..cf4fb9c 100644
--- a/resources/config/neuron.yaml
+++ b/resources/config/neuron.yaml
@@ -4,7 +4,6 @@
 system:
   timezone: UTC
   base_path: resources
-  routes_path: resources/config
 
 logging:
   destination: \Neuron\Log\Destination\File
@@ -82,3 +81,18 @@ member:
   # Email verification token expiration time (in minutes)
   # Tokens older than this will be considered invalid
   verification_token_expiration_minutes: 60
+
+# Exception Handling Configuration
+exceptions:
+  # Exceptions that should pass through to application-level handlers
+  # instead of being caught by the framework's error handler.
+  # This is useful for custom error pages or specific exception handling logic.
+  passthrough:
+    # CMS-specific exceptions that require special handling (redirects, specific error pages)
+    - Neuron\Cms\Exceptions\UnauthenticatedException
+    - Neuron\Cms\Exceptions\EmailVerificationRequiredException
+    - Neuron\Cms\Exceptions\CsrfValidationException
+    # Additional exceptions can be added as needed
+    # - RuntimeException
+    # - LogicException
+    # - InvalidArgumentException
diff --git a/src/Bootstrap.php b/src/Bootstrap.php
index 754254a..1c71939 100644
--- a/src/Bootstrap.php
+++ b/src/Bootstrap.php
@@ -42,14 +42,6 @@
 
 function boot( string $configPath ) : Application
 {
-	// Register CMS exceptions that should bubble up to application-level handlers
-	// These exceptions require special handling (redirects, specific error pages)
-	Registry::getInstance()->set( 'BubbleExceptions', [
-		'Neuron\\Cms\\Exceptions\\UnauthenticatedException',
-		'Neuron\\Cms\\Exceptions\\EmailVerificationRequiredException',
-		'Neuron\\Cms\\Exceptions\\CsrfValidationException'
-	] );
-
 	// Build and register the DI container BEFORE MVC boot
 	// This ensures the container is available to initializers during boot
 	try
diff --git a/src/Cms/Controllers/Admin/Categories.php b/src/Cms/Controllers/Admin/Categories.php
index fee3131..4eda93f 100644
--- a/src/Cms/Controllers/Admin/Categories.php
+++ b/src/Cms/Controllers/Admin/Categories.php
@@ -35,37 +35,23 @@ class Categories extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param ICategoryRepository|null $categoryRepository
-	 * @param ICategoryCreator|null $categoryCreator
-	 * @param ICategoryUpdater|null $categoryUpdater
+	 * @param ICategoryRepository $categoryRepository
+	 * @param ICategoryCreator $categoryCreator
+	 * @param ICategoryUpdater $categoryUpdater
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?ICategoryRepository $categoryRepository = null,
-		?ICategoryCreator $categoryCreator = null,
-		?ICategoryUpdater $categoryUpdater = null
+		ICategoryRepository $categoryRepository,
+		ICategoryCreator $categoryCreator,
+		ICategoryUpdater $categoryUpdater
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $categoryRepository === null )
-		{
-			throw new \InvalidArgumentException( 'ICategoryRepository must be injected' );
-		}
 		$this->_categoryRepository = $categoryRepository;
-
-		if( $categoryCreator === null )
-		{
-			throw new \InvalidArgumentException( 'ICategoryCreator must be injected' );
-		}
 		$this->_categoryCreator = $categoryCreator;
-
-		if( $categoryUpdater === null )
-		{
-			throw new \InvalidArgumentException( 'ICategoryUpdater must be injected' );
-		}
 		$this->_categoryUpdater = $categoryUpdater;
 	}
 
diff --git a/src/Cms/Controllers/Admin/Dashboard.php b/src/Cms/Controllers/Admin/Dashboard.php
index 5aa9743..36ce7f4 100644
--- a/src/Cms/Controllers/Admin/Dashboard.php
+++ b/src/Cms/Controllers/Admin/Dashboard.php
@@ -4,6 +4,7 @@
 
 use Neuron\Cms\Auth\SessionManager;
 use Neuron\Cms\Controllers\Content;
+use Neuron\Cms\Enums\FlashMessageType;
 use Neuron\Core\Exceptions\NotFound;
 use Neuron\Data\Settings\SettingManager;
 use Neuron\Mvc\IMvcApplication;
@@ -54,6 +55,8 @@ public function index( Request $request ): string
 			->description( 'Admin Dashboard' )
 			->withCurrentUser()
 			->withCsrfToken()
+			->with( 'Error', $this->getSessionManager()->getFlash( FlashMessageType::ERROR->value ) )
+			->with( 'Success', $this->getSessionManager()->getFlash( FlashMessageType::SUCCESS->value ) )
 			->render( 'index', 'admin' );
 	}
 }
diff --git a/src/Cms/Controllers/Admin/EventCategories.php b/src/Cms/Controllers/Admin/EventCategories.php
index dd2d1c8..78507f5 100644
--- a/src/Cms/Controllers/Admin/EventCategories.php
+++ b/src/Cms/Controllers/Admin/EventCategories.php
@@ -35,38 +35,24 @@ class EventCategories extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IEventCategoryRepository|null $repository
-	 * @param IEventCategoryCreator|null $creator
-	 * @param IEventCategoryUpdater|null $updater
+	 * @param IEventCategoryRepository $repository
+	 * @param IEventCategoryCreator $creator
+	 * @param IEventCategoryUpdater $updater
 	 * @throws \Exception
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IEventCategoryRepository $repository = null,
-		?IEventCategoryCreator $creator = null,
-		?IEventCategoryUpdater $updater = null
+		IEventCategoryRepository $repository,
+		IEventCategoryCreator $creator,
+		IEventCategoryUpdater $updater
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $repository === null )
-		{
-			throw new \InvalidArgumentException( 'IEventCategoryRepository must be injected' );
-		}
 		$this->_repository = $repository;
-
-		if( $creator === null )
-		{
-			throw new \InvalidArgumentException( 'IEventCategoryCreator must be injected' );
-		}
 		$this->_creator = $creator;
-
-		if( $updater === null )
-		{
-			throw new \InvalidArgumentException( 'IEventCategoryUpdater must be injected' );
-		}
 		$this->_updater = $updater;
 	}
 
diff --git a/src/Cms/Controllers/Admin/Events.php b/src/Cms/Controllers/Admin/Events.php
index 372872d..5fdb93d 100644
--- a/src/Cms/Controllers/Admin/Events.php
+++ b/src/Cms/Controllers/Admin/Events.php
@@ -39,45 +39,26 @@ class Events extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IEventRepository|null $eventRepository
-	 * @param IEventCategoryRepository|null $categoryRepository
-	 * @param IEventCreator|null $creator
-	 * @param IEventUpdater|null $updater
+	 * @param IEventRepository $eventRepository
+	 * @param IEventCategoryRepository $categoryRepository
+	 * @param IEventCreator $creator
+	 * @param IEventUpdater $updater
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IEventRepository $eventRepository = null,
-		?IEventCategoryRepository $categoryRepository = null,
-		?IEventCreator $creator = null,
-		?IEventUpdater $updater = null
+		IEventRepository $eventRepository,
+		IEventCategoryRepository $categoryRepository,
+		IEventCreator $creator,
+		IEventUpdater $updater
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $eventRepository === null )
-		{
-			throw new \InvalidArgumentException( 'IEventRepository must be injected' );
-		}
 		$this->_eventRepository = $eventRepository;
-
-		if( $categoryRepository === null )
-		{
-			throw new \InvalidArgumentException( 'IEventCategoryRepository must be injected' );
-		}
 		$this->_categoryRepository = $categoryRepository;
-
-		if( $creator === null )
-		{
-			throw new \InvalidArgumentException( 'IEventCreator must be injected' );
-		}
 		$this->_creator = $creator;
-
-		if( $updater === null )
-		{
-			throw new \InvalidArgumentException( 'IEventUpdater must be injected' );
-		}
 		$this->_updater = $updater;
 	}
 
diff --git a/src/Cms/Controllers/Admin/Media.php b/src/Cms/Controllers/Admin/Media.php
index 5de0a2d..c1f241c 100644
--- a/src/Cms/Controllers/Admin/Media.php
+++ b/src/Cms/Controllers/Admin/Media.php
@@ -35,30 +35,21 @@ class Media extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param CloudinaryUploader|null $uploader
-	 * @param MediaValidator|null $validator
+	 * @param CloudinaryUploader $uploader
+	 * @param MediaValidator $validator
 	 * @throws \Exception
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?CloudinaryUploader $uploader = null,
-		?MediaValidator $validator = null
+		CloudinaryUploader $uploader,
+		MediaValidator $validator
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $uploader === null )
-		{
-			throw new \InvalidArgumentException( 'CloudinaryUploader must be injected' );
-		}
 		$this->_uploader = $uploader;
-
-		if( $validator === null )
-		{
-			throw new \InvalidArgumentException( 'MediaValidator must be injected' );
-		}
 		$this->_validator = $validator;
 	}
 
diff --git a/src/Cms/Controllers/Admin/Pages.php b/src/Cms/Controllers/Admin/Pages.php
index 2ea2695..fb08a76 100644
--- a/src/Cms/Controllers/Admin/Pages.php
+++ b/src/Cms/Controllers/Admin/Pages.php
@@ -39,37 +39,23 @@ class Pages extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IPageRepository|null $pageRepository
-	 * @param IPageCreator|null $pageCreator
-	 * @param IPageUpdater|null $pageUpdater
+	 * @param IPageRepository $pageRepository
+	 * @param IPageCreator $pageCreator
+	 * @param IPageUpdater $pageUpdater
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IPageRepository $pageRepository = null,
-		?IPageCreator $pageCreator = null,
-		?IPageUpdater $pageUpdater = null
+		IPageRepository $pageRepository,
+		IPageCreator $pageCreator,
+		IPageUpdater $pageUpdater
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $pageRepository === null )
-		{
-			throw new \InvalidArgumentException( 'IPageRepository must be injected' );
-		}
 		$this->_pageRepository = $pageRepository;
-
-		if( $pageCreator === null )
-		{
-			throw new \InvalidArgumentException( 'IPageCreator must be injected' );
-		}
 		$this->_pageCreator = $pageCreator;
-
-		if( $pageUpdater === null )
-		{
-			throw new \InvalidArgumentException( 'IPageUpdater must be injected' );
-		}
 		$this->_pageUpdater = $pageUpdater;
 	}
 
diff --git a/src/Cms/Controllers/Admin/Posts.php b/src/Cms/Controllers/Admin/Posts.php
index eb8dce4..c5c44cf 100644
--- a/src/Cms/Controllers/Admin/Posts.php
+++ b/src/Cms/Controllers/Admin/Posts.php
@@ -44,61 +44,32 @@ class Posts extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IPostRepository|null $postRepository
-	 * @param ICategoryRepository|null $categoryRepository
-	 * @param ITagRepository|null $tagRepository
-	 * @param IPostCreator|null $postCreator
-	 * @param IPostUpdater|null $postUpdater
-	 * @param IPostDeleter|null $postDeleter
+	 * @param IPostRepository $postRepository
+	 * @param ICategoryRepository $categoryRepository
+	 * @param ITagRepository $tagRepository
+	 * @param IPostCreator $postCreator
+	 * @param IPostUpdater $postUpdater
+	 * @param IPostDeleter $postDeleter
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IPostRepository $postRepository = null,
-		?ICategoryRepository $categoryRepository = null,
-		?ITagRepository $tagRepository = null,
-		?IPostCreator $postCreator = null,
-		?IPostUpdater $postUpdater = null,
-		?IPostDeleter $postDeleter = null
+		IPostRepository $postRepository,
+		ICategoryRepository $categoryRepository,
+		ITagRepository $tagRepository,
+		IPostCreator $postCreator,
+		IPostUpdater $postUpdater,
+		IPostDeleter $postDeleter
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $postRepository === null )
-		{
-			throw new \InvalidArgumentException( 'IPostRepository must be injected' );
-		}
 		$this->_postRepository = $postRepository;
-
-		if( $categoryRepository === null )
-		{
-			throw new \InvalidArgumentException( 'ICategoryRepository must be injected' );
-		}
 		$this->_categoryRepository = $categoryRepository;
-
-		if( $tagRepository === null )
-		{
-			throw new \InvalidArgumentException( 'ITagRepository must be injected' );
-		}
 		$this->_tagRepository = $tagRepository;
-
-		if( $postCreator === null )
-		{
-			throw new \InvalidArgumentException( 'IPostCreator must be injected' );
-		}
 		$this->_postCreator = $postCreator;
-
-		if( $postUpdater === null )
-		{
-			throw new \InvalidArgumentException( 'IPostUpdater must be injected' );
-		}
 		$this->_postUpdater = $postUpdater;
-
-		if( $postDeleter === null )
-		{
-			throw new \InvalidArgumentException( 'IPostDeleter must be injected' );
-		}
 		$this->_postDeleter = $postDeleter;
 	}
 
diff --git a/src/Cms/Controllers/Admin/Profile.php b/src/Cms/Controllers/Admin/Profile.php
index 90dd72a..65c8a54 100644
--- a/src/Cms/Controllers/Admin/Profile.php
+++ b/src/Cms/Controllers/Admin/Profile.php
@@ -32,38 +32,24 @@ class Profile extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IUserRepository|null $repository
-	 * @param PasswordHasher|null $hasher
-	 * @param IUserUpdater|null $userUpdater
+	 * @param IUserRepository $repository
+	 * @param PasswordHasher $hasher
+	 * @param IUserUpdater $userUpdater
 	 * @throws \Exception
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IUserRepository $repository = null,
-		?PasswordHasher $hasher = null,
-		?IUserUpdater $userUpdater = null
+		IUserRepository $repository,
+		PasswordHasher $hasher,
+		IUserUpdater $userUpdater
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $repository === null )
-		{
-			throw new \InvalidArgumentException( 'IUserRepository must be injected' );
-		}
 		$this->_repository = $repository;
-
-		if( $hasher === null )
-		{
-			throw new \InvalidArgumentException( 'PasswordHasher must be injected' );
-		}
 		$this->_hasher = $hasher;
-
-		if( $userUpdater === null )
-		{
-			throw new \InvalidArgumentException( 'IUserUpdater must be injected' );
-		}
 		$this->_userUpdater = $userUpdater;
 	}
 
diff --git a/src/Cms/Controllers/Admin/Tags.php b/src/Cms/Controllers/Admin/Tags.php
index 24d34f0..9a09d4b 100644
--- a/src/Cms/Controllers/Admin/Tags.php
+++ b/src/Cms/Controllers/Admin/Tags.php
@@ -33,30 +33,21 @@ class Tags extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param ITagRepository|null $tagRepository
-	 * @param SlugGenerator|null $slugGenerator
+	 * @param ITagRepository $tagRepository
+	 * @param SlugGenerator $slugGenerator
 	 * @throws \Exception
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?ITagRepository $tagRepository = null,
-		?SlugGenerator $slugGenerator = null
+		ITagRepository $tagRepository,
+		SlugGenerator $slugGenerator
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $tagRepository === null )
-		{
-			throw new \InvalidArgumentException( 'ITagRepository must be injected' );
-		}
 		$this->_tagRepository = $tagRepository;
-
-		if( $slugGenerator === null )
-		{
-			throw new \InvalidArgumentException( 'SlugGenerator must be injected' );
-		}
 		$this->_slugGenerator = $slugGenerator;
 	}
 
diff --git a/src/Cms/Controllers/Admin/Users.php b/src/Cms/Controllers/Admin/Users.php
index f285565..bed5ac7 100644
--- a/src/Cms/Controllers/Admin/Users.php
+++ b/src/Cms/Controllers/Admin/Users.php
@@ -36,45 +36,26 @@ class Users extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IUserRepository|null $repository
-	 * @param IUserCreator|null $userCreator
-	 * @param IUserUpdater|null $userUpdater
-	 * @param IUserDeleter|null $userDeleter
+	 * @param IUserRepository $repository
+	 * @param IUserCreator $userCreator
+	 * @param IUserUpdater $userUpdater
+	 * @param IUserDeleter $userDeleter
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IUserRepository $repository = null,
-		?IUserCreator $userCreator = null,
-		?IUserUpdater $userUpdater = null,
-		?IUserDeleter $userDeleter = null
+		IUserRepository $repository,
+		IUserCreator $userCreator,
+		IUserUpdater $userUpdater,
+		IUserDeleter $userDeleter
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $repository === null )
-		{
-			throw new \InvalidArgumentException( 'IUserRepository must be injected' );
-		}
 		$this->_repository = $repository;
-
-		if( $userCreator === null )
-		{
-			throw new \InvalidArgumentException( 'IUserCreator must be injected' );
-		}
 		$this->_userCreator = $userCreator;
-
-		if( $userUpdater === null )
-		{
-			throw new \InvalidArgumentException( 'IUserUpdater must be injected' );
-		}
 		$this->_userUpdater = $userUpdater;
-
-		if( $userDeleter === null )
-		{
-			throw new \InvalidArgumentException( 'IUserDeleter must be injected' );
-		}
 		$this->_userDeleter = $userDeleter;
 	}
 
diff --git a/src/Cms/Controllers/Auth/Login.php b/src/Cms/Controllers/Auth/Login.php
index e680679..949e931 100644
--- a/src/Cms/Controllers/Auth/Login.php
+++ b/src/Cms/Controllers/Auth/Login.php
@@ -102,7 +102,7 @@ public function login( Request $request ): never
 		}
 
 		// Attempt authentication
-		if( !$this->_authentication->attempt( $dto->username, $dto->password, $dto->remember ) )
+		if( !$this->_authentication->attempt( $dto->username, $dto->password, $dto->remember ?? false ) )
 		{
 			$this->redirect( 'login', [], [FlashMessageType::ERROR->value, 'Invalid username or password.'] );
 		}
diff --git a/src/Cms/Controllers/Auth/PasswordReset.php b/src/Cms/Controllers/Auth/PasswordReset.php
index fbb81f5..de8ddbd 100644
--- a/src/Cms/Controllers/Auth/PasswordReset.php
+++ b/src/Cms/Controllers/Auth/PasswordReset.php
@@ -32,22 +32,16 @@ class PasswordReset extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IPasswordResetter|null $passwordResetter
-	 * @throws \Exception
+	 * @param IPasswordResetter $passwordResetter
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IPasswordResetter $passwordResetter = null
+		IPasswordResetter $passwordResetter
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
-
-		if( $passwordResetter === null )
-		{
-			throw new \InvalidArgumentException( 'IPasswordResetter must be injected' );
-		}
 		$this->_passwordResetter = $passwordResetter;
 	}
 
diff --git a/src/Cms/Controllers/Blog.php b/src/Cms/Controllers/Blog.php
index 03e3035..419ac30 100644
--- a/src/Cms/Controllers/Blog.php
+++ b/src/Cms/Controllers/Blog.php
@@ -33,43 +33,26 @@ class Blog extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IPostRepository|null $postRepository
-	 * @param ICategoryRepository|null $categoryRepository
-	 * @param ITagRepository|null $tagRepository
-	 * @param IUserRepository|null $userRepository
-	 * @param EditorJsRenderer|null $renderer
+	 * @param IPostRepository $postRepository
+	 * @param ICategoryRepository $categoryRepository
+	 * @param ITagRepository $tagRepository
+	 * @param IUserRepository $userRepository
+	 * @param EditorJsRenderer $renderer
 	 * @throws \Exception
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IPostRepository $postRepository = null,
-		?ICategoryRepository $categoryRepository = null,
-		?ITagRepository $tagRepository = null,
-		?IUserRepository $userRepository = null,
-		?EditorJsRenderer $renderer = null
+		IPostRepository $postRepository,
+		ICategoryRepository $categoryRepository,
+		ITagRepository $tagRepository,
+		IUserRepository $userRepository,
+		EditorJsRenderer $renderer
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		// Pure dependency injection - no service locator fallback
-		if( $postRepository === null ) {
-			throw new \InvalidArgumentException( 'IPostRepository must be injected' );
-		}
-		if( $categoryRepository === null ) {
-			throw new \InvalidArgumentException( 'ICategoryRepository must be injected' );
-		}
-		if( $tagRepository === null ) {
-			throw new \InvalidArgumentException( 'ITagRepository must be injected' );
-		}
-		if( $userRepository === null ) {
-			throw new \InvalidArgumentException( 'IUserRepository must be injected' );
-		}
-		if( $renderer === null ) {
-			throw new \InvalidArgumentException( 'EditorJsRenderer must be injected' );
-		}
-
 		$this->_postRepository = $postRepository;
 		$this->_categoryRepository = $categoryRepository;
 		$this->_tagRepository = $tagRepository;
@@ -119,20 +102,20 @@ public function show( Request $request ): string
 		$slug = $request->getRouteParameter( 'slug', '' );
 		$post = $this->_postRepository->findBySlug( $slug );
 
-		if( !$post )
+		$responseStatus = HttpResponseStatus::OK;
+
+		if( !$post || !$post->isPublished() )
 		{
 			$post = new Post();
 			$post->setTitle( 'Article Not Found' );
 			$post->setBody( 'The requested article does not exist.' );
 			$post->setSlug( $slug );
+			$responseStatus = HttpResponseStatus::NOT_FOUND;
 		}
 		else
 		{
 			// Increment view count for published posts
-			if( $post->isPublished() )
-			{
-				$this->_postRepository->incrementViewCount( $post->getId() );
-			}
+			$this->_postRepository->incrementViewCount( $post->getId() );
 		}
 
 		$categories = $this->_categoryRepository->all();
@@ -142,8 +125,14 @@ public function show( Request $request ): string
 		$content = $post->getContent();
 		$renderedContent = $this->_renderer?->render( $content ) ?? (is_array($content) ? json_encode($content) : $content);
 
+		// Fallback to plain text body if Editor.js content is empty
+		if( empty( trim( $renderedContent ) ) && !empty( $post->getBody() ) )
+		{
+			$renderedContent = '<p>' . htmlspecialchars( $post->getBody() ) . '</p>';
+		}
+
 		return $this->renderHtml(
-			HttpResponseStatus::OK,
+			$responseStatus,
 			[
 				'Categories' => $categories,
 				'Tags'        => $tags,
@@ -165,7 +154,7 @@ public function show( Request $request ): string
 	#[Get('/author/:username', name: 'blog_author')]
 	public function author( Request $request ): string
 	{
-		$authorName = $request->getRouteParameter( 'author', '' );
+		$authorName = $request->getRouteParameter( 'username', '' );
 
 		// Look up user by username
 		$user = $this->_userRepository->findByUsername( $authorName );
@@ -204,7 +193,7 @@ public function author( Request $request ): string
 	#[Get('/tag/:slug', name: 'blog_tag')]
 	public function tag( Request $request ): string
 	{
-		$tagSlug = $request->getRouteParameter( 'tag', '' );
+		$tagSlug = $request->getRouteParameter( 'slug', '' );
 		$tag = $this->_tagRepository->findBySlug( $tagSlug );
 
 		if( !$tag )
@@ -245,7 +234,7 @@ public function tag( Request $request ): string
 	#[Get('/category/:slug', name: 'blog_category')]
 	public function category( Request $request ): string
 	{
-		$categorySlug = $request->getRouteParameter( 'category', '' );
+		$categorySlug = $request->getRouteParameter( 'slug', '' );
 		$category = $this->_categoryRepository->findBySlug( $categorySlug );
 
 		if( !$category )
diff --git a/src/Cms/Controllers/Calendar.php b/src/Cms/Controllers/Calendar.php
index 0947928..05b6e11 100644
--- a/src/Cms/Controllers/Calendar.php
+++ b/src/Cms/Controllers/Calendar.php
@@ -30,30 +30,21 @@ class Calendar extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IEventRepository|null $eventRepository
-	 * @param IEventCategoryRepository|null $categoryRepository
+	 * @param IEventRepository $eventRepository
+	 * @param IEventCategoryRepository $categoryRepository
 	 * @throws \Exception
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IEventRepository $eventRepository = null,
-		?IEventCategoryRepository $categoryRepository = null
+		IEventRepository $eventRepository,
+		IEventCategoryRepository $categoryRepository
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $eventRepository === null )
-		{
-			throw new \InvalidArgumentException( 'IEventRepository must be injected' );
-		}
 		$this->_eventRepository = $eventRepository;
-
-		if( $categoryRepository === null )
-		{
-			throw new \InvalidArgumentException( 'IEventCategoryRepository must be injected' );
-		}
 		$this->_categoryRepository = $categoryRepository;
 	}
 
diff --git a/src/Cms/Controllers/Member/Profile.php b/src/Cms/Controllers/Member/Profile.php
index 6e3c0d0..78e4395 100644
--- a/src/Cms/Controllers/Member/Profile.php
+++ b/src/Cms/Controllers/Member/Profile.php
@@ -31,38 +31,24 @@ class Profile extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IUserRepository|null $repository
-	 * @param PasswordHasher|null $hasher
-	 * @param IUserUpdater|null $userUpdater
+	 * @param IUserRepository $repository
+	 * @param PasswordHasher $hasher
+	 * @param IUserUpdater $userUpdater
 	 * @throws \Exception
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IUserRepository $repository = null,
-		?PasswordHasher $hasher = null,
-		?IUserUpdater $userUpdater = null
+		IUserRepository $repository,
+		PasswordHasher $hasher,
+		IUserUpdater $userUpdater
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $repository === null )
-		{
-			throw new \InvalidArgumentException( 'IUserRepository must be injected' );
-		}
 		$this->_repository = $repository;
-
-		if( $hasher === null )
-		{
-			throw new \InvalidArgumentException( 'PasswordHasher must be injected' );
-		}
 		$this->_hasher = $hasher;
-
-		if( $userUpdater === null )
-		{
-			throw new \InvalidArgumentException( 'IUserUpdater must be injected' );
-		}
 		$this->_userUpdater = $userUpdater;
 	}
 
diff --git a/src/Cms/Controllers/Member/Registration.php b/src/Cms/Controllers/Member/Registration.php
index 083d8f6..23051f7 100644
--- a/src/Cms/Controllers/Member/Registration.php
+++ b/src/Cms/Controllers/Member/Registration.php
@@ -36,46 +36,27 @@ class Registration extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IRegistrationService|null $registrationService
-	 * @param IEmailVerifier|null $emailVerifier
-	 * @param ResendVerificationThrottle|null $resendThrottle
-	 * @param IIpResolver|null $ipResolver
+	 * @param IRegistrationService $registrationService
+	 * @param IEmailVerifier $emailVerifier
+	 * @param ResendVerificationThrottle $resendThrottle
+	 * @param IIpResolver $ipResolver
 	 * @throws \Exception
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IRegistrationService $registrationService = null,
-		?IEmailVerifier $emailVerifier = null,
-		?ResendVerificationThrottle $resendThrottle = null,
-		?IIpResolver $ipResolver = null
+		IRegistrationService $registrationService,
+		IEmailVerifier $emailVerifier,
+		ResendVerificationThrottle $resendThrottle,
+		IIpResolver $ipResolver
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		if( $registrationService === null )
-		{
-			throw new \InvalidArgumentException( 'IRegistrationService must be injected' );
-		}
 		$this->_registrationService = $registrationService;
-
-		if( $emailVerifier === null )
-		{
-			throw new \InvalidArgumentException( 'IEmailVerifier must be injected' );
-		}
 		$this->_emailVerifier = $emailVerifier;
-
-		if( $resendThrottle === null )
-		{
-			throw new \InvalidArgumentException( 'ResendVerificationThrottle must be injected' );
-		}
 		$this->_resendThrottle = $resendThrottle;
-
-		if( $ipResolver === null )
-		{
-			throw new \InvalidArgumentException( 'IIpResolver must be injected' );
-		}
 		$this->_ipResolver = $ipResolver;
 	}
 
diff --git a/src/Cms/Controllers/Pages.php b/src/Cms/Controllers/Pages.php
index 68b4818..50ffd4f 100644
--- a/src/Cms/Controllers/Pages.php
+++ b/src/Cms/Controllers/Pages.php
@@ -34,31 +34,20 @@ class Pages extends Content
 	 * @param IMvcApplication $app
 	 * @param SettingManager $settings
 	 * @param SessionManager $sessionManager
-	 * @param IPageRepository|null $pageRepository
-	 * @param EditorJsRenderer|null $renderer
+	 * @param IPageRepository $pageRepository
+	 * @param EditorJsRenderer $renderer
 	 * @throws \Exception
 	 */
 	public function __construct(
 		IMvcApplication $app,
 		SettingManager $settings,
 		SessionManager $sessionManager,
-		?IPageRepository $pageRepository = null,
-		?EditorJsRenderer $renderer = null
+		IPageRepository $pageRepository,
+		EditorJsRenderer $renderer
 	)
 	{
 		parent::__construct( $app, $settings, $sessionManager );
 
-		// Pure dependency injection - no service locator fallback
-		if( $pageRepository === null )
-		{
-			throw new \InvalidArgumentException( 'IPageRepository must be injected' );
-		}
-
-		if( $renderer === null )
-		{
-			throw new \InvalidArgumentException( 'EditorJsRenderer must be injected' );
-		}
-
 		$this->_pageRepository = $pageRepository;
 		$this->_renderer = $renderer;
 	}
diff --git a/tests/Unit/BootstrapTest.php b/tests/Unit/BootstrapTest.php
index 53c36a0..e43edf1 100644
--- a/tests/Unit/BootstrapTest.php
+++ b/tests/Unit/BootstrapTest.php
@@ -176,42 +176,55 @@ public function testBootDelegatesToMvc()
 	}
 
 	/**
-	 * Test that CMS Boot registers bubble exceptions in Registry
+	 * Test that CMS Boot loads passthrough exceptions from YAML config
 	 */
-	public function testBootRegistersBubbleExceptions()
+	public function testBootLoadsPassthroughExceptionsFromConfig()
 	{
-		// Clear registry before test
-		Registry::getInstance()->set( 'BubbleExceptions', null );
-
-		// Boot the CMS application
-		$app = Boot( 'examples/config' );
-
-		// Verify bubble exceptions are registered
-		$bubbleExceptions = Registry::getInstance()->get( 'BubbleExceptions' );
-
-		$this->assertIsArray( $bubbleExceptions );
-		$this->assertContains( 'Neuron\\Cms\\Exceptions\\UnauthenticatedException', $bubbleExceptions );
-		$this->assertContains( 'Neuron\\Cms\\Exceptions\\EmailVerificationRequiredException', $bubbleExceptions );
-		$this->assertContains( 'Neuron\\Cms\\Exceptions\\CsrfValidationException', $bubbleExceptions );
+		// Boot a fresh application in isolation to avoid Registry state pollution from previous tests
+		// Use a separate PHP process to ensure clean state
+		$code = <<<'PHP'
+		require 'vendor/autoload.php';
+		$app = Neuron\Cms\boot('examples/config');
+		$exceptions = Neuron\Patterns\Registry::getInstance()->get('PassthroughExceptions');
+		echo json_encode($exceptions);
+		PHP;
+
+		$output = shell_exec("php -r " . escapeshellarg($code));
+		$passthroughExceptions = json_decode($output, true);
+
+		$this->assertIsArray( $passthroughExceptions, 'PassthroughExceptions should be an array' );
+		$this->assertNotEmpty( $passthroughExceptions, 'PassthroughExceptions should not be empty. Got: ' . json_encode( $passthroughExceptions ) );
+
+		// These are defined in examples/config/neuron.yaml
+		$this->assertContains( 'Neuron\\Cms\\Exceptions\\UnauthenticatedException', $passthroughExceptions );
+		$this->assertContains( 'Neuron\\Cms\\Exceptions\\EmailVerificationRequiredException', $passthroughExceptions );
+		$this->assertContains( 'Neuron\\Cms\\Exceptions\\CsrfValidationException', $passthroughExceptions );
 	}
 
 	/**
-	 * Test that registered bubble exceptions are the correct classes
+	 * Test that passthrough exceptions loaded from config are valid classes
 	 */
-	public function testBubbleExceptionsAreValidClasses()
+	public function testPassthroughExceptionsAreValidClasses()
 	{
-		// Boot the CMS application
-		$app = Boot( 'examples/config' );
+		// Boot a fresh application in isolation
+		$code = <<<'PHP'
+		require 'vendor/autoload.php';
+		$app = Neuron\Cms\boot('examples/config');
+		$exceptions = Neuron\Patterns\Registry::getInstance()->get('PassthroughExceptions');
+		echo json_encode($exceptions);
+		PHP;
+
+		$output = shell_exec("php -r " . escapeshellarg($code));
+		$passthroughExceptions = json_decode($output, true);
 
-		// Get registered exceptions
-		$bubbleExceptions = Registry::getInstance()->get( 'BubbleExceptions' );
+		$this->assertIsArray( $passthroughExceptions );
 
 		// Verify each exception class exists
-		foreach( $bubbleExceptions as $exceptionClass )
+		foreach( $passthroughExceptions as $exceptionClass )
 		{
 			$this->assertTrue(
 				class_exists( $exceptionClass ),
-				"Bubble exception class does not exist: $exceptionClass"
+				"Passthrough exception class does not exist: $exceptionClass"
 			);
 		}
 	}
diff --git a/tests/Unit/Cms/Auth/CsrfFilterTest.php b/tests/Unit/Cms/Auth/CsrfFilterTest.php
index c7e6e7c..6a7e332 100644
--- a/tests/Unit/Cms/Auth/CsrfFilterTest.php
+++ b/tests/Unit/Cms/Auth/CsrfFilterTest.php
@@ -263,20 +263,19 @@ public function testPostTokenExtractionLimitation(): void
 		$method->setAccessible( true );
 		$token = $method->invoke( $this->_filter );
 
-		// In unit tests, filter_input(INPUT_POST) returns null because
-		// it reads from PHP's input buffer, not $_POST. Therefore, the
-		// method falls back to the header token even though we set POST.
+		// POST token should take precedence over header token.
+		// The implementation uses Neuron\Data\Filters\Post which can read $_POST
+		// directly, so it works correctly in both unit tests and real requests.
 		$this->assertEquals(
-			'header-token',
+			'post-token',
 			$token,
-			'Unit tests fall back to header because filter_input(INPUT_POST) cannot read $_POST'
+			'POST token takes precedence over header token'
 		);
 
 		// Verify our test setup was correct (POST was set)
 		$this->assertEquals( 'post-token', $_POST['csrf_token'] );
 
-		// In real requests (integration/E2E tests), POST would take precedence
-		// and the token would be 'post-token', not 'header-token'
+		// This behavior is now consistent in both unit tests and real requests
 
 		// Cleanup
 		unset( $_POST['csrf_token'] );
diff --git a/tests/Unit/Cms/BlogControllerTest.php b/tests/Unit/Cms/BlogControllerTest.php
index ad00b81..bef0e21 100644
--- a/tests/Unit/Cms/BlogControllerTest.php
+++ b/tests/Unit/Cms/BlogControllerTest.php
@@ -386,7 +386,7 @@ public function testTagFiltersPostsByTag(): void
 
 		$blog = $this->createBlogWithInjectedRepositories();
 		$request = new Request();
-		$request->setRouteParameters( [ 'tag' => $tag->getSlug() ] );
+		$request->setRouteParameters( [ 'slug' => $tag->getSlug() ] );
 		$result = $blog->tag( $request );
 
 		$this->assertIsString( $result );
@@ -404,7 +404,7 @@ public function testCategoryFiltersPostsByCategory(): void
 
 		$blog = $this->createBlogWithInjectedRepositories();
 		$request = new Request();
-		$request->setRouteParameters( [ 'category' => $category->getSlug() ] );
+		$request->setRouteParameters( [ 'slug' => $category->getSlug() ] );
 		$result = $blog->category( $request );
 
 		$this->assertIsString( $result );
@@ -422,11 +422,11 @@ public function testAuthorFiltersPostsByAuthor(): void
 
 		$blog = $this->createBlogWithInjectedRepositories();
 
-		// Create mock request with author parameter
+		// Create mock request with username parameter
 		$request = $this->createMock( Request::class );
 		$request->expects( $this->once() )
 			->method( 'getRouteParameter' )
-			->with( 'author', '' )
+			->with( 'username', '' )
 			->willReturn( 'author1' );
 
 		$result = $blog->author( $request );
diff --git a/tests/Unit/Cms/Controllers/Admin/CategoriesTest.php b/tests/Unit/Cms/Controllers/Admin/CategoriesTest.php
index b27d32f..dbb6abd 100644
--- a/tests/Unit/Cms/Controllers/Admin/CategoriesTest.php
+++ b/tests/Unit/Cms/Controllers/Admin/CategoriesTest.php
@@ -84,7 +84,7 @@ public function testConstructorThrowsExceptionWithoutSettingManager(): void
 
 	public function testConstructorThrowsExceptionWithoutCategoryRepository(): void
 	{
-		$this->expectException( \InvalidArgumentException::class );
+		$this->expectException( \TypeError::class );
 
 		$mockSettings = Registry::getInstance()->get( 'Settings' );
 		$mockSessionManager = $this->createMock( SessionManager::class );
diff --git a/tests/Unit/Cms/Controllers/Admin/PostsTest.php b/tests/Unit/Cms/Controllers/Admin/PostsTest.php
index c0706bb..229cf9b 100644
--- a/tests/Unit/Cms/Controllers/Admin/PostsTest.php
+++ b/tests/Unit/Cms/Controllers/Admin/PostsTest.php
@@ -85,7 +85,7 @@ public function testConstructorThrowsExceptionWithoutSettingManager(): void
 
 	public function testConstructorThrowsExceptionWithoutPostRepository(): void
 	{
-		$this->expectException( \InvalidArgumentException::class );
+		$this->expectException( \TypeError::class );
 
 		$mockSettings = Registry::getInstance()->get( 'Settings' );
 		$mockSessionManager = $this->createMock( SessionManager::class );
diff --git a/tests/Unit/Cms/Controllers/Admin/UsersTest.php b/tests/Unit/Cms/Controllers/Admin/UsersTest.php
index 75b0b30..ec6f481 100644
--- a/tests/Unit/Cms/Controllers/Admin/UsersTest.php
+++ b/tests/Unit/Cms/Controllers/Admin/UsersTest.php
@@ -78,7 +78,7 @@ public function testConstructorThrowsExceptionWithoutSettingManager(): void
 
 	public function testConstructorThrowsExceptionWithoutUserRepository(): void
 	{
-		$this->expectException( \InvalidArgumentException::class );
+		$this->expectException( \TypeError::class );
 
 		$mockSettings = Registry::getInstance()->get( 'Settings' );
 		$mockSessionManager = $this->createMock( SessionManager::class );
diff --git a/tests/Unit/Cms/Controllers/Auth/PasswordResetTest.php b/tests/Unit/Cms/Controllers/Auth/PasswordResetTest.php
index 4aa086d..b1a5ffd 100644
--- a/tests/Unit/Cms/Controllers/Auth/PasswordResetTest.php
+++ b/tests/Unit/Cms/Controllers/Auth/PasswordResetTest.php
@@ -111,7 +111,7 @@ public function testConstructorWithDependencies(): void
 
 	public function testConstructorThrowsExceptionWithoutPasswordResetter(): void
 	{
-		$this->expectException( \InvalidArgumentException::class );
+		$this->expectException( \TypeError::class );
 
 		$mockSettingManager = Registry::getInstance()->get( 'Settings' );
 		$mockSessionManager = $this->createMock( \Neuron\Cms\Auth\SessionManager::class );
diff --git a/tests/Unit/Cms/Controllers/Member/RegistrationTest.php b/tests/Unit/Cms/Controllers/Member/RegistrationTest.php
index 32afdc8..6685d0d 100644
--- a/tests/Unit/Cms/Controllers/Member/RegistrationTest.php
+++ b/tests/Unit/Cms/Controllers/Member/RegistrationTest.php
@@ -126,7 +126,7 @@ public function testConstructorWithAllDependencies(): void
 
 	public function testConstructorThrowsExceptionWithoutRegistrationService(): void
 	{
-		$this->expectException( \InvalidArgumentException::class );
+		$this->expectException( \TypeError::class );
 
 		new Registration(
 			$this->mockApp,
@@ -141,7 +141,7 @@ public function testConstructorThrowsExceptionWithoutRegistrationService(): void
 
 	public function testConstructorThrowsExceptionWithoutEmailVerifier(): void
 	{
-		$this->expectException( \InvalidArgumentException::class );
+		$this->expectException( \TypeError::class );
 
 		new Registration(
 			$this->mockApp,
@@ -156,7 +156,7 @@ public function testConstructorThrowsExceptionWithoutEmailVerifier(): void
 
 	public function testConstructorThrowsExceptionWithoutResendThrottle(): void
 	{
-		$this->expectException( \InvalidArgumentException::class );
+		$this->expectException( \TypeError::class );
 
 		new Registration(
 			$this->mockApp,
@@ -171,7 +171,7 @@ public function testConstructorThrowsExceptionWithoutResendThrottle(): void
 
 	public function testConstructorThrowsExceptionWithoutIpResolver(): void
 	{
-		$this->expectException( \InvalidArgumentException::class );
+		$this->expectException( \TypeError::class );
 
 		new Registration(
 			$this->mockApp,