feat: add cucumber gherkin-style E2E test framework

- Install @cucumber/cucumber and cucumber-pretty dependencies
- Create Cucumber configuration with tsx loader for TypeScript support
- Add step definitions for common navigation, form interactions, and assertions
- Add authentication step definitions for login/logout flows
- Create feature files for user registration and authentication
- Support multiple auth contexts (player, tournament admin, club admin)
- Configure package.json scripts for running Cucumber tests

Key features:
- Gherkin syntax (Given/When/Then) for behavior-driven testing
- Browser-only interactions (no direct database access)
- Dev site testing (tests run against running dev server)
- Happy path focus for acceptance testing
- Integration with existing TypeScript project

e2e/cucumber/features/authentication.feature

@@ -0,0 +1,35 @@
+Feature: User Authentication
+  As a registered user
+  I want to log in and log out
+  So that I can access my account features
+
+  @happy-path @authentication
+  Scenario: Login with valid credentials
+    Given I am logged in as a player
+    When I go to the home page
+    Then I should see "Sign out"
+
+  @happy-path @authentication
+  Scenario: Logout successfully
+    Given I am logged in as a player
+    When I click the "Sign out" button
+    Then I should be redirected to the login page
+
+  @negative-test @authentication
+  Scenario: Login with invalid credentials
+    Given I am on the login page
+    When I log in with invalid credentials
+    Then I should see an error message
+    And I should remain on the login page
+
+  @happy-path @authentication
+  Scenario: Navigate to login page
+    Given I am on the home page
+    When I click the "Log in" link
+    Then I should be on the login page
+
+  @happy-path @authentication
+  Scenario: Navigate to registration from login
+    Given I am on the login page
+    When I click the "Create an account" link
+    Then I should be on the registration page