MVP in a Weekend Spec

Example

User: An app for my piano students. I assign pieces; students log each practice session (piece, minutes) and I see a weekly total per student. Students only see their own logs. A session is at most 180 minutes. Wish list: lesson payments, badges, a leaderboard, chat.

Result (excerpt):

CORE FLOW: a student logs a practice session for an assigned piece; the teacher sees it in that student's weekly total
ASSUMED: the week runs Monday to Sunday
REQUIREMENTS MAP: teacher assigns pieces → PROMPT 1 · session with piece and minutes → PROMPT 1
at most 180 minutes per session → PROMPT 1 · students see only their own logs → PROMPT 1
weekly total per student → PROMPT 2
DEFERRED: lesson payments (needs a provider and testing), badges and chat (not needed to log practice)
FLAGGED: leaderboard (shows students' practice to each other; many may be children, so decide what is visible first)
TIME CHECK: 6 prompts plus fixes; fits one weekend

PROMPT 1 (start in Plan mode, then Build): "Build a practice log for a piano teacher.
Two roles, teacher and student, each with login. The teacher creates pieces and
assigns them to students. A student logs a practice session: date, assigned piece,
minutes, at most 180 (the form refuses more with 'Up to 180 minutes per session').
Students see and edit only their own sessions; the database refuses other students'
records, not just the pages. The teacher sees every student's sessions. Pages: login,
my pieces, log session, my sessions, teacher's student list. Leave out payments,
badges, chat and leaderboards."
Check: log a session as student A; as student B, the list is empty.
Permission check: as student B, open the address of A's session page; nothing is shown.
Limit check: 180 minutes saves; 181 is refused with the message.

PROMPT 2 weekly totals: "On the teacher's student list, show each student's total
practice minutes for the current week, Monday to Sunday, next to their name. Only
the teacher sees this page. Do not change the log form."
Check: as student A, log 30 and 45 minutes this week; the teacher sees 75 next to A.

SETUP AND LAUNCH:
- First privileged accounts: "Make the account with my email the only teacher. New
  sign-ups are always students, and no page lets a user change their own role."
  Check: a fresh sign-up lands as a student.

Illustrative example; your output will differ.