Admin login required — same email/password as the Admin Panel.
Rule: one mobile number = one account. For each phone number below with 2+ accounts, pick which one to keep (defaults to a genuinely paid/enrolled account over a Free-only one, then whichever has given the most tests) — the others are retired (never hard-deleted: their history stays in Firestore, login is disabled, and any paid access/fees they had are transferred onto the kept account).
For students who once chose a custom Student ID: makes their Student ID their phone number too, so they can log in with just their phone number + their existing password (no reset needed). Run the duplicate cleanup above FIRST for any phone number this flags as a conflict.
Fixes two related bugs found 2026-09-12: granting real access (via "Refresh Karo" / duplicate access-fix)
never cleared a leftover 3-Day Trial timer (demoExpiresAt) or Free-for-All flag
(openAccess) on the same account. Either one alone, even after real access exists, can wrongly
sign a student out ("your free demo period has ended") or — for openAccess — actually block
real course content at the Firestore security-rules level, not just mis-color the admin panel's name
red/gold instead of green. Only accounts with a real enrollment AND at least one leftover flag are
affected — a genuine free/demo-only account is left completely untouched.