Increase timeout to 3m for FactChecker Agent

[alexheifetz]

This pull request updates the fact-checking logic to improve reliability when interacting with large language models (LLMs) by adding explicit timeout settings to LLM calls. The most important changes are:

LLM Timeout Handling:

• All LLM invocations in FactChecker.java now include a timeout of 3 minutes to prevent long-running or hanging requests. This is applied both when checking individual factual assertions and during the deduplication step. [1] [2]

Dependency Imports:

• Added the import for java.time.Duration to support the new timeout configuration.