Streak validity and one-day freeze policy

DEC-0002 - Streak validity and one-day freeze policy

Context

Need simple streak logic to encourage consistency without heavy friction.

Decision

• A day counts for streak if user completes and submits any exercise.
• No constraints on difficulty, time spent, or score.
• If user misses one day after an active streak, system grants exactly one freeze day.
• If user still does not submit during freeze day, streak resets.
• No extra rescue/freeze mechanism.

Rationale

Simple rules are easier to understand and reduce dropout caused by punishment complexity.

Implications

• Streak events can trigger reactivation notifications.
• Freeze is a lightweight retention buffer.

Validation signal

Users should recover from one-off misses without feeling punished, while long misses still reset properly.