AI Tutor reminder permission fallback, daily cap, and login behavior policy

DEC-0028 - AI Tutor reminder permission fallback, daily cap, and login behavior policy

Context

After fixing reminder channel/timing/stop rules, edge behavior around push permission and login state must be explicit to avoid ambiguity.

Decision

Permission fallback:

• If web push is disabled or unavailable, keep in-app reminder only.
• Do not fallback to extra channels for this daily required reminder.

Daily cap:

• Max one reminder per day at fixed local-time slot.
• Do not schedule same-day retry or second reminder for daily required reminder.

Not-logged-in behavior:

• If learner is not logged in during reminder slot, do not send catch-up reminder later the same day.
• On next login, show current-day required not-completed state only.

Simplicity posture:

• No adaptive reminder frequency or catch-up queue in V2 baseline.

Rationale

Permission-based fallback avoids channel escalation surprises. One-reminder cap reduces fatigue and keeps operations cheap. No catch-up queue avoids delayed noise and keeps day-state interpretation straightforward.