Fix: Handle object rendering in UI

[Patel230]

Summary

• Fixes #2725 - React crashes when rendering workflow output objects
• Adds robust utility to safely format various output types
• Prevents UI crashes when nodes return structured objects like {text, type}

Changes

• Created format-output.ts utility with deep object traversal
• Updated chat components to use the new formatting utility
• Added comprehensive unit tests
• Handles edge cases: circular refs, nested objects, arrays, XSS protection

Test Plan

• [x] Tested with LLM outputs returning {text: "content", type: "response"}
• [x] Tested with nested objects and arrays
• [x] Verified no React rendering errors
• [x] Unit tests cover all scenarios