User Model

The portal has five kinds of users — parent, teacher, student, admin, and developer — but only one users table and no role column.

Roles are derived, not stored

Application::rolesForUser() is the single implementation. A user’s roles come from row existence:

Two consequences worth spelling out:

• Roles are additive. A teacher who is also a parent holds both roles. An adult who takes lessons themselves gets a student_profiles row on their own users row — there is no separate “adult student” concept.
• A soft-deleted user holds no roles at all. is_deleted short-circuits role resolution, so a deleted user reaches no dashboard, appears in no lists, and cannot sign in — but their rows and history remain.

Dashboard routing

rolesForUser() returns roles in priority order, and the site root routes to the first match:

admin → teacher → parent → student → /profile/

The /profile/ fallback covers a freshly invited account that an admin has not linked to anything yet. A user who holds several roles lands on the highest-priority dashboard and reaches the others through the navigation. The same role list drives which menu the top bar shows (ApplicationUI).

Developer is a modifier, not a sixth role

users.is_developer is a separate flag that does not participate in routing. Combined with is_admin, it unlocks the Admin > Maintenance section: migrations, the activity log, the email log, and server logs. Think of it as a permission modifier on the admin role for the people who operate the software itself.

Signing in

• email is the login identifier and is nullable-unique: child students often have no email and simply cannot sign in — their schedule is visible to their parents instead.
• password_hash of '' means “cannot sign in yet.” A password arrives via an invite or the forgot-password flow; until then the account exists (it can be scheduled, billed, and noted) without being a login.

Family structure

There is no families table. A family is expressed entirely through parenthood edges (parent user ↔ child user, with an optional mother/father/guardian role), which handles shared custody, multiple guardians, and households that don’t fit a single-family model. Billing follows the same shape: charges attach to the student, and a parent’s balance is the sum over their linked children.