fix(frontend): fix multiple UI bugs and improve robustness

[zhoufengen]

Summary

This PR fixes several frontend bugs and improves code robustness across the workspace components and core modules.

Changes

Bug Fixes

1. Null guard in useRenameThread (core/threads/hooks.ts)

   • The onSuccess callback called oldData.map() without checking for null, which would crash if the query cache was empty.
   • Added the same if (oldData == null) { return oldData; } guard already used in useDeleteThread.

2. Response check in loadArtifactContent (core/artifacts/loader.ts)

   • fetch() result was read with response.text() without checking response.ok, which could display error HTML as artifact content.
   • Added if (!response.ok) check that throws a descriptive error.

3. Clipboard API error handling in CopyButton (components/workspace/copy-button.tsx)

   • navigator.clipboard.writeText() was fire-and-forget (void), so the "copied" indicator would show even if the write failed.
   • Now awaits the promise in a try/catch and only shows the copied state on success.

Accessibility

4. Invalid ARIA roles in message skeleton (components/workspace/messages/skeleton.tsx)
   • role="human-message" and role="assistant-message" are not valid WAI-ARIA role values.
   • Replaced with data-role attributes to preserve the semantic intent without violating the spec.

UI

5. Dark mode support in TodoList (components/workspace/todo-list.tsx)
   • Hardcoded bg-white broke dark mode rendering.
   • Replaced with bg-background, the theme-aware class used throughout the workspace.

Code Quality

6. Remove console.log from production code (core/config/index.ts, core/api/api-client.ts)
   • Removed debug console.log statements that would output to the browser console in production.

Testing

• All changes are minimal and focused on correctness.
• Each fix follows existing patterns already established in the codebase.

[CLAassistant]

All committers have signed the CLA.

[WillemJiang]

@zhoufengen, thanks for your contribution. Please fix the lint error.

[Copilot]

Pull request overview

This PR addresses several small but user-visible frontend issues in the DeerFlow workspace UI and core client utilities, improving robustness and accessibility while removing stray debug logging.

Changes:

• Hardened React Query cache updates (null/undefined guards) and artifact loading (response.ok check).
• Improved clipboard copy UX by awaiting clipboard writes before showing the “copied” state.
• Fixed UI/accessibility issues (dark-mode background class; replaced invalid ARIA roles with data attributes) and removed production console.logs.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
frontend/src/core/threads/hooks.ts	Prevents potential crash when renaming if cached thread list is missing/undefined.
frontend/src/core/config/index.ts	Removes debug logging from base URL resolution.
frontend/src/core/artifacts/loader.ts	Throws a descriptive error when artifact fetch fails instead of treating error HTML as content.
frontend/src/core/api/api-client.ts	Removes debug logging during API client creation.
frontend/src/components/workspace/todo-list.tsx	Uses theme-aware bg-background to support dark mode.
frontend/src/components/workspace/messages/skeleton.tsx	Replaces invalid role values with data-role attributes to avoid ARIA violations.
frontend/src/components/workspace/copy-button.tsx	Awaits clipboard write and only shows “copied” state on success.