fix: use error detail for login credential error messages

[hztBUAA]

Summary

Fixes #2787

The login form displayed the wrong error message for incorrect credentials because it read error.message (HTTP status text like "Unauthorized") instead of error.detail (the actual error reason like "credentialsSignin").

Changes

• Import ClientError from @chainlit/react-client in LoginForm.tsx
• Updated the catch block to check for ClientError.detail first, which contains the meaningful error reason (e.g., "credentialsSignin")
• Falls back to Error.message when detail is not available, preserving backward compatibility

How it works

When the /login endpoint returns an error, the fetch wrapper in api/index.tsx creates a ClientError with:

• message = HTTP status text (e.g., "Unauthorized")
• detail = parsed response body detail (e.g., "credentialsSignin")

Previously, LoginForm used err.message for the translation key lookup (auth.login.errors.unauthorized), which didn't match any translation. Now it uses err.detail (auth.login.errors.credentialssignin), which correctly maps to the intended error message.

Test Plan

• Enter incorrect credentials on the login screen -> proper translated error message is displayed
• Non-ClientError exceptions still display error.message as before
• ClientError without detail falls back to error.message

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Summary by cubic

Fixes #2787. Use ClientError.detail in LoginForm so invalid credential attempts display the correct translated error, falling back to Error.message when detail is missing.

^{Written for commit 18a8187. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 1 file

[dokterbob]

Does this close/address #2787 ?