fix: harden NewsService toJSON() against malformed LLM output

[shivv23]

Description

Improve the toJSON() method in NewsService to handle malformed LLM outputs gracefully.

Changes:

1. Remove debug print statements - Eliminated unnecessary logging statements
2. Add try/except block - Catch IndexError and AttributeError for malformed data
3. Handle empty/partial responses - Return empty list instead of crashing
4. Validate data length - Skip items with less than 4 fields

Related Issues

• Closes Harden NewsService LLM output parsing #118

Motivation and Context

LLM outputs can be unpredictable. The previous implementation would crash on malformed data or leave debug prints in production.

How Has This Been Tested

• Syntax verification passed
• All changes are defensive and non-breaking

Checklist

• My code follows the code style of this project
• I have read the CONTRIBUTING document