feat: implement function to truncate json

[italojohnny]

This PR implements a utility function to truncate JSON and applies it to the vertex_build and transaction table fields to ensure consistent formatting of JSON-related data.

[codspeed-hq]

CodSpeed Performance Report

Merging #5811 will degrade performances by 21.3%

_{Comparing feat/json_truncation (8ee5c51) with main (1604526)}

Summary

⚡ 2 improvements
❌ 1 regressions
✅ 6 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	feat/json_truncation	Change
⚡	test_build_flow	4,239.2 ms	396.1 ms	×11
⚡	test_invalid_run_with_input_type_chat	29.3 ms	25.3 ms	+16%
❌	test_successful_run_with_input_type_any	274.8 ms	349.2 ms	-21.3%

[severfire]

@italojohnny will be those limits applied to json output of the models? like if i ask model to generate json output, will it be truncated?