AI Tutor plan missed-day, required completion, and optional-role policy

DEC-0026 - AI Tutor plan missed-day, required completion, and optional-role policy

Context

After locking plan structure and sourcing, daily execution rules must be explicit to avoid confusion and unnecessary complexity.

Decision

Missed-day handling:

• If learner misses a day, do not carry that required item forward.
• Continue with next day plan as scheduled.

Required completion definition:

• A day is counted as required-complete when learner submits the required exercise.

Optional item role:

• Optional exercise is bonus-only support.
• Optional does not replace required completion.
• Optional does not change high-attention exit or weekly official recovery confirmation.

Simplicity posture:

• No debt/catch-up mechanism for missed days in V2 baseline.

Rationale

Skipping missed-day backlog prevents pressure accumulation and keeps behavior predictable. Submission-based completion is clear and low-friction. Keeping optional strictly bonus avoids hidden rule complexity and preserves consistent recovery semantics.