Practice PYQ models

Folder: models/practice-pyq/

Taxonomy (catalog tree)

File	Level
`practice-pyq-subject.model.ts`	Subject (e.g. Polity)
`practice-pyq-topic.model.ts`	Topic under subject
`practice-pyq-subtopic.model.ts`	Subtopic under topic
`practice-pyq-question.model.ts`	Individual MCQ

practice-pyq-import-meta.schema.ts — metadata for bulk imports.

File	Purpose
`practice-pyq-user-question-card.model.ts`	SRS card: due date, ease, reps per user+question

Schedulers in services/practice-pyq-srs-scheduler.ts update these documents when user answers.


Subject
  └── Topic
        └── Subtopic
              └── Question
                    └── UserQuestionCard (per student)

One question document is shared; each student has their own card for scheduling.