[BUG] Some fields in schemas.py should be optional

[DavidDzgoev]

Description:
The Pydantic schemas in schemas.py are not fully accurate. Some fields could be optional, but they are currently required. This can lead to unnecessary validation errors when handling partial data.

Steps to reproduce:

1. Try to validate data where some fields are missing but should logically be optional.
2. The validation fails instead of allowing flexible input.

Expected behavior:

• Fields that are not always required should be marked as str | None or given default values.

Important Notes:

• Not all fields should be made optional immediately.
• It would be best to provide examples which allow you to know that field is optional

Suggested Fix:

• Review schemas.py and determine which fields should be optional.
• Update the Pydantic models accordingly.
• Add test cases to verify the changes.