fix: use answersDocId instead of testDocId when deleting answer document

[Karrrthik7]

Fixes #1861

Problem

The removeUserAnswer method in AnswerController was deleting the wrong Firestore document.
The code previously used:
userToUpdate.myAnswers[payload.testDocId].testDocId

However, testDocId represents the study identifier, not the Firestore document ID of the answer.
The UserAnswer model stores two fields:

• testDocId → study identifier
• answersDocId → Firestore document ID in the answers collection

Because of this mismatch, the system attempted to delete: answers/{testDocId}
instead of the actual answer document: answers/{answersDocId}
This left orphaned answer documents in Firestore when a cooperator was removed.

Solution

The deletion now uses answersDocId instead of testDocId:

const answerDocumentId =
  userToUpdate.myAnswers[payload.testDocId].answersDocId

This ensures the correct document in the answers collection is deleted.

Impact

• Prevents orphaned answer documents in Firestore
• Ensures cooperator removal cleans up associated answer data correctly
• Maintains data integrity for analytics and reporting

Files Changed: src/shared/controllers/AnswerController.js

Screenshots

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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