test: add role-based navigation tests verifying correct nav sections per user role

tests/ScadaLink.CentralUI.PlaywrightTests/PlaywrightFixture.cs

@@ -49,11 +49,17 @@ public class PlaywrightFixture : IAsyncLifetime
     }
 
     /// <summary>
-    /// Create a new page and log in with the test user.
+    /// Create a new page and log in with the default multi-role test user.
+    /// </summary>
+    public Task<IPage> NewAuthenticatedPageAsync() =>
+        NewAuthenticatedPageAsync(TestUsername, TestPassword);
+
+    /// <summary>
+    /// Create a new page and log in with specific credentials.
     /// Uses JavaScript fetch() to POST to /auth/login from within the browser,
     /// which sets the auth cookie in the browser context. Then navigates to the dashboard.
     /// </summary>
-    public async Task<IPage> NewAuthenticatedPageAsync()
+    public async Task<IPage> NewAuthenticatedPageAsync(string username, string password)
     {
         var page = await NewPageAsync();
 
@@ -63,24 +69,21 @@ public class PlaywrightFixture : IAsyncLifetime
 
         // POST to /auth/login via fetch() inside the browser.
         // This sets the auth cookie in the browser context automatically.
-        // Use redirect: 'follow' so the browser follows the 302 and the cookie is stored.
         var finalUrl = await page.EvaluateAsync<string>(@"
-            async () => {
+            async ([u, p]) => {
                 const resp = await fetch('/auth/login', {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
-                    body: 'username=' + encodeURIComponent('" + TestUsername + @"')
-                        + '&password=' + encodeURIComponent('" + TestPassword + @"'),
+                    body: 'username=' + encodeURIComponent(u) + '&password=' + encodeURIComponent(p),
                     redirect: 'follow'
                 });
                 return resp.url;
             }
-        ");
+        ", new object[] { username, password });
 
-        // The fetch followed the redirect. If it ended on /login, auth failed.
         if (finalUrl.Contains("/login"))
         {
-            throw new InvalidOperationException($"Login failed — redirected back to login: {finalUrl}");
+            throw new InvalidOperationException($"Login failed for '{username}' — redirected back to login: {finalUrl}");
         }
 
         // Navigate to the dashboard — cookie authenticates us