feat: доделал MS Auth для фронта

backend/UniVerse.Infrastructure/Services/AuthService.cs

@@ -30,16 +30,26 @@ public class AuthService : IAuthService
         _gamification = gamification;
     }
 
-    public async Task<AuthResult> LoginWithMicrosoftAsync(string authorizationCode)
+    public async Task<AuthResult> LoginWithMicrosoftAsync(string authorizationCode, string? redirectUri = null)
     {
         var tenantId = _config["AzureAd:TenantId"];
         var clientId = _config["AzureAd:ClientId"];
         var clientSecret = _config["AzureAd:ClientSecret"];
+        var instance = _config["AzureAd:Instance"] ?? "https://login.microsoftonline.com/";
+
+        if (string.IsNullOrWhiteSpace(tenantId) || string.IsNullOrWhiteSpace(clientId) || string.IsNullOrWhiteSpace(clientSecret))
+            throw new UnauthorizedException("Microsoft authentication is not configured (AzureAd:TenantId/ClientId/ClientSecret).");
+
+        var effectiveRedirectUri = redirectUri
+                                   ?? _config["AzureAd:RedirectUri"]
+                                   ?? "http://localhost:5173/auth/callback";
+
+        var authority = $"{instance.TrimEnd('/')}/{tenantId}";
         
         var app = ConfidentialClientApplicationBuilder.Create(clientId)
             .WithClientSecret(clientSecret)
-            .WithAuthority(new Uri($"https://login.microsoftonline.com/{tenantId}"))
-            .WithRedirectUri(_config["AzureAd:RedirectUri"] ?? "http://localhost:5173/auth/callback")
+            .WithAuthority(new Uri(authority))
+            .WithRedirectUri(effectiveRedirectUri)
             .Build();
 
         AuthenticationResult result;