refactor(models): removing unused models

[Skyline857]

Description Remove unnecessary models from the backend[#23]

Requirements: There are some models that are no longer relevant to our current database schema and should be removed such as invitation, member, family.

Test Steps

1. Setup Postman: Open Postman and create a new collection for your API tests.

Testing Endpoints:

Get All Kids:

Method: GET URL: http://localhost:8000/api/kids Headers: None Body: None

Expected Response: A success message with a status of 200. Create Kid:

Method: POST URL: http://localhost:8000/api/kids Headers: Content-Type: application/json Body (example): json { "name": "John Doe", "age": 10, "parent_id": "parent-id-123" } Expected Response: The created kid profile in JSON format with a status of 201.

Get Kid by ID:

Method: GET URL: http://localhost:8000/api/kids/kjkjk Headers: None Body: None Expected Response: A success message with a status of 200. Update Kid:

Method: PUT URL: http://localhost:8000/api/kids/kjkjk Headers: Content-Type: application/json Body (example):None Expected Response: A success message with a status of 200.

Delete Kid:

Method: DELETE URL: http://localhost:8000/api/kids/hjhjjh Headers: None Body: None Expected Response: A success message with a status of 200.

API Changes New Endpoints: None Removed Endpoints: None Modified Endpoints: None

Checklist Pull Request title includes the issue number and a brief description of the change. All changes should be tested and verified to work correctly. Code follows backend best practices. Branch names follow the conventions in the contributing file. Commit messages follow the naming conventions in the contributing file. No sensitive data or secrets are included in the codebase.