feat(role): reflect ReBAC doc with changes

docs/architecture/rebac-authorization.md

@@ -107,9 +107,19 @@ storage.access_grants
   expires_at   TIMESTAMPTZ NULL
 ```
 
-One row per `(subject, permission, resource)` triple. An "admin role on folder
+One row per `(subject, permission, resource)` triple. An "owner role on folder
 X for user Y" is 6 rows; a "viewer role" is 1 row.
 
+> **Note (D-Prep, 2026-06-17):** the role assignment has since pivoted into
+> a separate `storage.role_grants` table that stores **one row per role
+> assignment** rather than one per permission. `access_grants` stays
+> populated via dual-write during the transition; the engine reads the
+> role-keyed table for authz decisions. The cleanup PR drops
+> `access_grants` after the dual-write window. The historical role name
+> `Admin` was renamed to `Owner` at the same time, to disambiguate from
+> `UserRole::Admin` (user-account privilege) and match Drive plan
+> terminology.
+
 Cleanup is trigger-driven (`trg_cleanup_grants_folder`, …): when a resource or
 subject is deleted, all referencing grants disappear in the same transaction.
 

docs/plan/drive.md

@@ -44,6 +44,14 @@ recognise it instantly.
 
 ## Prerequisite — PR D-Prep: `access_grants → role_grants`
 
+**Status (2026-06-17): scope complete, ready to PR.** The schema migration
+runs cleanly against real sandbox data (38 role_grants rows produced,
+matching the audit's 29 viewer / 5 editor / 4 owner distribution, zero
+bundle mismatches). End-to-end Hurl test (`tests/api/role_grants.hurl`)
+covers create / atomic role update / revoke with both the canonical
+`"owner"` and the legacy `"admin"` compat wire format. Engine reads
+pivot to `role_grants` for authz decisions; `access_grants` stays
+populated via dual-write as the safety net for one release cycle.
 **Ratified 2026-06-16.** A separate PR lands BEFORE D0 that refactors
 `storage.access_grants` into `storage.role_grants` with role-bundle
 semantics:

docs/plan/plan-ReBAC-Permissions-Grants-Cascading.md

@@ -603,19 +603,28 @@ impl Role {
         match self {
             Role::Viewer    => &[Permission::Read],
             Role::Commenter   => &[Permission::Read, Permission::Comment],
+            Role::Contributor => &[Permission::Read, Permission::Create],
             Role::Editor      => &[Permission::Read, Permission::Comment,
                                    Permission::Create, Permission::Update],
-            Role::Manager   => &[Permission::Read, Permission::Comment,
+            Role::Owner       => &[Permission::Read, Permission::Comment,
                                    Permission::Create, Permission::Update,
-                                 Permission::Share],
+                                   Permission::Share, Permission::Delete,
-            Role::Admin     => &[Permission::Read, Permission::Comment,
+                                   Permission::Manage],
-                                 Permission::Create, Permission::Update,
-                                 Permission::Share, Permission::Delete],
         }
     }
 }
 ```
 
+> **Note (D-Prep, 2026-06-17):** the `Manager` role was retired before shipping
+> (its bundle was a strict subset of `Owner`); the historical `Admin` role was
+> renamed to `Owner` to disambiguate from `UserRole::Admin` (the user-account
+> privilege) and match Drive plan terminology. `Contributor` is the new
+> drop-zone role. The actual on-the-wire enum lives in
+> `src/application/dtos/grant_dto.rs`; that file is the canonical source of
+> truth for bundle expansion. The pivot to role-keyed storage (`role_grants`
+> table) also happened in D-Prep — see
+> `docs/architecture/rebac-authorization.md` for the dual-write timeline.
+
 ### `POST /api/grants` accepts either shape
 
 ```json