fix: align run() invocation key with chain input

[prajakta128]

Summary

This PR fixes a mismatch between the expected chain input key and the key used during invocation in run().

Issue

The chain is configured to use:

"question"

But invocation used:

"query"

This mismatch can lead to incorrect or empty prompt input.

Fix

Replaced:

"query" → "question"

Impact

• Aligns invocation with chain definition
• Prevents missing input issues
• Minimal safe fix

[prajakta128]

Hi! I noticed a small mismatch between the chain input key and invocation.
I fixed it by aligning the key to question.
Happy to make changes if needed. Thanks!