- Improved the `IsDuplicateKeyError` function to utilize structured error messages for better accuracy in identifying duplicate key errors.
- Introduced `duplicateKeyMessages` and `hasStructuredWriteException` functions to parse and extract relevant information from MongoDB error messages.
- Updated `DuplicateKeyMatchesField` to match duplicate key errors against specific fields by analyzing error messages rather than relying on substring matching.
This refactor enhances the clarity and reliability of duplicate key error handling, ensuring more precise identification of conflicts in MongoDB operations.
Map E11000 from the per-collection phone index to friendly conflict
errors and skip redundant GetByPhone when the phone is unchanged.
Not blocking: IAT test DB may need a one-off dedupe for index build;
phone uniqueness is per collection (users vs customers), not global.