Remove noisy comment

Author: myieye

backend/FwLite/FwLiteShared/Auth/OAuthClient.cs

@@ -291,10 +291,6 @@ internal enum SilentAuthFailureOutcome
         _ => SilentAuthFailureOutcome.KeepCachedCredentials,
     };
 
-    //Classifies AcquireTokenInteractive failures by exception type, not message/code: MSAL's "oidc_failure"
-    //is an unpublished string literal, whereas the inner HttpRequestException is a reliable offline signal.
-    //A cancel is treated as a cancel regardless of connectivity; offline with a warm OIDC cache also surfaces
-    //here, but the user has already seen the browser fail. null means rethrow (global handler surfaces it).
     internal static LoginResult? ClassifyInteractiveLoginFailure(Exception e) => e switch
     {
         MsalServiceException { InnerException: HttpRequestException } => LoginResult.Offline,

frontend/viewer/src/lib/errors/global-errors.test.ts

@@ -0,0 +1,50 @@
+import {describe, expect, it} from 'vitest';
+
+import {processErrorIntoDetails} from './global-errors';
+
+describe('processErrorIntoDetails', () => {
+  it('splits a .NET error at the first stack frame', () => {
+    const message = [
+      'System.InvalidOperationException: Everything is broken.',
+      '   at FwLiteShared.Services.Foo.Bar(String x)',
+      '   at FwLiteShared.Services.Foo.Baz()',
+    ].join('\n');
+
+    const {message: title, detail} = processErrorIntoDetails({message, error: null});
+
+    expect(title).toBe('System.InvalidOperationException: Everything is broken.');
+    expect(detail).toContain('at FwLiteShared.Services.Foo.Bar(String x)');
+  });
+
+  it('splits at the inner-exception marker that precedes the outer frames, keeping a wrapped error\'s title short', () => {
+    // MSAL wrapping an Android network failure: the whole " ---> " cascade comes before the first managed frame
+    const message = [
+      'Microsoft.Identity.Client.MsalServiceException: Failed to retrieve OIDC configuration. See inner exception.',
+      ' ---> System.Net.Http.HttpRequestException: Connection failure',
+      ' ---> Java.Net.UnknownHostException: Unable to resolve host',
+      '   at Java.Interop.JniEnvironment.InstanceMethods.CallVoidMethod()',
+    ].join('\n');
+
+    const {message: title, detail} = processErrorIntoDetails({message, error: null});
+
+    expect(title).toBe('Microsoft.Identity.Client.MsalServiceException: Failed to retrieve OIDC configuration. See inner exception.');
+    expect(detail).toContain('---> System.Net.Http.HttpRequestException: Connection failure');
+  });
+
+  it('keeps the whole message as the title when there is no .NET stack', () => {
+    const {message: title, detail} = processErrorIntoDetails({message: 'plain error', error: null});
+
+    expect(title).toBe('plain error');
+    expect(detail).toBeUndefined();
+  });
+
+  it('does not repeat a JS Error message in both title and detail', () => {
+    const error = new Error('boom');
+
+    const {message: title, detail} = processErrorIntoDetails({message: 'Uncaught Error: boom', error});
+
+    expect(title).toBe('boom');
+    expect(detail).not.toContain('boom');
+    expect(detail).toContain('at ');
+  });
+});