Summary

This PR adds the ability to select multiple traces and apply feedback scores to all of them at once, as requested in #1010.

Changes

New Files

• useTraceFeedbackScoreBatchMutation.ts - API hook for the batch feedback scores endpoint
• BulkAnnotateDialog/ - Dialog component for bulk annotation

Modified Files

• TracesActionsPanel.tsx - Added "Annotate selected" button

Features

• Select multiple traces using checkboxes
• Click "Annotate selected" button to open bulk annotation dialog
• Choose from existing feedback score definitions:
  • Numerical: Slider input with min/max range
  • Categorical: Dropdown with category options
  • Boolean: True/False dropdown
• Add optional reason for the annotation
• Apply the same score to all selected traces in one operation

Testing

1. Navigate to a project's Traces tab
2. Select multiple traces using checkboxes
3. Click the "Annotate selected" button (MessageSquarePlus icon)
4. Select a feedback score definition
5. Set the value and optionally add a reason
6. Click "Apply to all"
7. Verify scores are applied to all selected traces

Screenshots

(Screenshots can be added after testing)

Resolves #1010