database schema update needs to be smooth

### Present Condition:

In case of any changes made to the DB schema in `models.py`
In all environments, database needs to be reset else it throws up an error.

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### Requirement:

If any change is there in the schema, new tables should be created while deleting older ones, so that no DB reset is required on production as well.

Start by reviewing models.py and the current database reset behavior described in the issue. Identify how schema changes are currently handled and define a safe migration path for production. The work is done when schema changes create the required new tables and remove obsolete ones without requiring a database reset.

Written by the indexing model from the issue text.