Add Data Validation for Plan Creation

[DimitrovK]

Add validation to ensure Plan models have consistent data when created through the admin or API.
Tasks

Add validation that monthly/yearly price IDs exist in Stripe
Add validation for plan ordering
Ensure at least one price ID is provided
Add custom validation methods to Plan model
Add validation tests

Files to modify

• core/models.py
• core/admin.py
• core/tests.py

[Dwid4r]

I'd like to work on this issue.

[DimitrovK]

Sure, I've assigned it over to you.

[skalwaghe-56]

Can you assign this to me?

[adityasingh-0803]

i would like to work on this

[inzamol]

/assign

[Varun270]

Hey @Dwid4r , You still working on this one?

[DancingPeacock-31]

hey ,I want to work on this issue, please assign me under the hacktoberfest 2025 . I would really appreciate for it. Thanks!!!