🔧 fix: Streamline Builder Links and Enhance UI Consistency

[danny-avila]

Summary

I removed unnecessary key checks for agent and assistant builder links, relied on endpoint configuration for enabling builder links in the side navigation, improved UI consistency by using theme background colors, included the iconURL in Bedrock client initialization, and eliminated unnecessary filtering for agent file_search files.

• Removed unnecessary keyProvided checks for agent builder link in the side navigation.
• Relied on endpoint configuration disableBuilder instead of parameters to enable builder links in the side navigation.
• Applied theme background colors in the SidePanel component to enhance UI consistency.
• Included iconURL in Bedrock client initialization to ensure proper icon display.
• Eliminated unnecessary filtering for agent file_search files in FileSearch.tsx.

Change Type

• Bug fix (non-breaking change which fixes an issue)

Checklist

• My code adheres to this project's style guidelines
• I have performed a self-review of my own code
• I have commented in any complex areas of my code
• I have made pertinent documentation changes
• My changes do not introduce new warnings
• Local unit tests pass with my changes