1. Users

• id (PK)
• email (Unique, CSV se aata hai)
• name (Optional, profile mein update kar sakta hai)
• avatar (Email/name-based auto-generated, e.g., "ND" for "Nikhil Dubey")
• is_admin BOOLEAN DEFAULT FALSE
• created_at, updated_at
• Purpose:
  • Sirf CSV mein listed emails se hi signup/login hoga.
  • Admin (ChaiCode) bhi isi table mein hoga (with is_admin flag).

2. Cohorts

• id (PK)
• name (e.g., "WebDev Jan 2024")
• description
• created_by (FK → users.id, admin)
• Purpose:
  • CSV upload karke cohorts create honge.
  • Student login ke time cohort select karega.

3. UserCohorts

• user_id (FK → users.id)
• cohort_id (FK → cohorts.id)
• joined_at
• Purpose:
  • Ek student multiple cohorts ka part ho sakta hai.
  • Login ke baad saare cohorts dikhayenge.

4. Groups