Enhance Input Validation for API Serializers

[Sachin-NK]

Right now, the API serializers don’t do much to check the input, which can lead to problems. This issue aims to make validation stronger to keep the data accurate and improve error messages. The plan is to add:

Field-level checks: Make sure things like data types, lengths, and formats are correct.
Object-level validation: Add more complex rules that involve multiple fields.

These improvements will help catch errors early and keep the data clean.

[Sachin-NK]

working on this