docs(phase7): document the business/product architecture foundation

New: ROOTNODE_ACADEMY_BUSINESS_AND_PRODUCT_ARCHITECTURE.md (canonical business/platform
bridge — course families, delivery modes, BUILT NOW/PHASE 7 BUILT/FUTURE), OFFERING_AND_
REGISTRATION_MODEL.md (lifecycle diagrams, capacity mechanics), STUDENT_GUARDIAN_DATA_
MODEL.md (data minimization, RBAC, legal-review items), SCHOOL_AND_COMMUNITY_DELIVERY_
ARCHITECTURE.md (organization/location mapping, explicitly not multi-tenancy),
PHASE7_PRODUCT_ARCHITECTURE.md (phase summary).

Updated: WEBSITE_ENROLLMENT_INTEGRATION.md (documented future offering/registration flow,
current live contract unchanged), platform/README.md (test list).

Co-Authored-By: Claude Sonnet 5 <[email protected]>

platform/README.md

@@ -106,6 +106,12 @@ further instructor accounts from the Instructors tab).
   prerequisite graph (no cycles, no missing nodes), the strengthened Capstone gate (ROOT 09 AND
   ROOT 12 both required) in both directions, the new orientation module, and an explicit check
   that no age/grade gate exists anywhere in enrollment.
+- `test/e2e-phase7.js` — organizations/locations, guardians and student-guardian relationships,
+  curriculum packages (reference-only, never a content clone), offerings (capacity, server-
+  defined status transitions), the registration lifecycle through agreement acceptance and
+  conversion to a real enrollment, registration/guardian RBAC, explicit age-guidance-is-never-
+  an-authorization-check verification, and confirmation that existing ROOT_ V1/self-paced/
+  classroom flows are unaffected.
 
 `infra/scripts/drills/` also holds real-Lab dress rehearsals per phase (Phase 6D/6E foundations,
 Phase 6F's multi-student pilot and full end-to-end V1 journey) — see each script's own header