SRIE ACADEMY — SCHOOL DATA FOUNDATION PATCH
Draft 0.1 / Stage 1

Adds:
- schools table
- school_user membership pivot
- school_courses assignment pivot
- School model
- Eloquent relationships in User and Course models

Status:
- Created only in isolated development copy.
- Not applied to original script or any database.
- Does not yet add school-admin controllers/routes, tenant middleware, or report exports.
- Do not run migrations against production.
- Migration/runtime tests require the project's dependencies and a disposable development database.

Before merge:
1. Review schema and foreign keys against the target database engine.
2. Run migration up/down on a disposable database.
3. Add feature tests for membership and course assignment.
4. Add backend policies/scopes before exposing Admin Sekolah screens.
5. Add audit logging for assignment changes.
