feat: add deepseek integration

[devin-ai-integration]

Add DeepSeek Integration

This PR adds DeepSeek integration to the langtrace application, replicating the changes from langtrace-internal. The changes include:

Changes

• Added DeepSeek logo (deepseek.jpeg) to public directory
• Added DeepSeek color configurations in vendor-metadata.tsx
  • Badge color: bg-blue-500
  • Vendor color: bg-blue-200
• Added DeepSeek pricing table in constants.ts for deepseek-coder model
  • Input cost: $0.00014 per token
  • Output cost: $0.00028 per token
• Added DeepSeek to SUPPORTED_VENDORS

Testing

⚠️ Note: Unable to verify UI changes due to development environment setup issues. However, all file changes have been verified to match the langtrace-internal implementation exactly:

• Logo file size matches (4560 bytes)
• Color configurations match brand requirements
• Pricing table values are correct
• SUPPORTED_VENDORS entry is properly configured

Additional Information

Link to Devin run: https://preview.devin.ai/devin/6c36e23fb9de4ba8804bc048677c27c6

If you have any feedback, you can leave comments in the PR and I'll address them in the app!