feat(auth)!: membership grade is not a capability channel — close the sys_member.role vocabulary (ADR-0108, #3723) (#3802)

`sys_member.role` answers "what is your standing in this organization". It
does not answer "what may you do" — that is what positions are for.

`resolve-authz-context` projects EVERY value stored in `sys_member.role` into
`current_user.positions`, so a business role handed out through the membership
role was capability, granted with none of ADR-0090 D12's controls: no
`granted_by`, no ADR-0091 validity window, no BU-subtree check, no
`assignablePermissionSets` allowlist. ADR-0057 D4 ruled that out ("never as
the authority for RBAC"), ADR-0090 D3's word ban restates it (distribution =
`position`), and ADR-0095 D3 keeps the better-auth role out of the enforcement
path. No ADR authorized the widening — it arrived as a bug fix (#3747) and was
then made automatic in every host (#3779).

The vocabulary is closed to owner / admin / delegated_admin / member.
`additionalOrgRoles`, `org-roles.ts` and the `kernel:ready` derivation hook are
removed; capability at admission time goes through ADR-0105 D8 invitation
placement, which is governed and reaches further (a delegated admin may use it
within their subtree, where the membership-role route was org-admin-only).

Both reversed changesets were unreleased, so no published version ever offered
the behaviour. Downstream `objectstack-ai/cloud` audited at b168e94: no
compile-time or runtime impact.

Also: lint's MEMBERSHIP_TIERS now derives from BUILTIN_MEMBERSHIP_ROLES. The
hand-kept copy carried `guest`, which the select has never offered, so an
approver naming it resolved to nobody while the lint whose job is to catch that
stayed silent.

Author: os-zhuang

.changeset/adr-0105-d8-delegated-admin-org-role.md

@@ -14,8 +14,8 @@ subtree. That gate is implemented, unit-proven and reachable — but no principa
 could reach it in a state where it did anything:
 
 - better-auth grants `invitation: ["create"]` to `owner` and `admin` only
-  (`memberAc` holds `invitation: []`, and roles registered through
-  `additionalOrgRoles` inherited that empty statement);
+  (`memberAc` holds `invitation: []`, which every other registered role
+  inherits);
 - under a wall-enforcing posture, owners and admins are auto-elevated to
   `organization_admin` (`auto-org-admin-grant.ts`), which carries the wildcard
   `modifyAllRecords` that makes `isTenantAdmin()` true — and the gate

.changeset/app-org-roles-storable.md

@@ -0,0 +1,77 @@
+---
+'@objectstack/plugin-auth': minor
+'@objectstack/platform-objects': minor
+'@objectstack/spec': minor
+'@objectstack/lint': patch
+'@objectstack/cli': patch
+'@objectstack/verify': patch
+'@objectstack/plugin-dev': patch
+'@objectstack/runtime': patch
+---
+
+feat(auth)!: membership grade is not a capability channel — the `sys_member.role`
+vocabulary is closed (ADR-0108, #3723)
+
+`sys_member.role` answers "what is your standing in this organization". It does
+not answer "what may you do" — that is what positions are for. One column was
+answering both.
+
+`resolve-authz-context` projects EVERY value stored in `sys_member.role` into
+`current_user.positions`, alongside the rows read from `sys_user_position`. So a
+business role handed out through the membership role *was* capability — granted
+with none of the position system's controls: no `granted_by`, no ADR-0091
+validity window, no BU-subtree check, no `assignablePermissionSets` allowlist.
+That is what ADR-0057 D4 ruled out ("feed the names to better-auth **only** so
+invitations are accepted — **never as the authority for RBAC**"), what
+ADR-0090 D3's word ban restates (distribution = `position`), and what
+ADR-0095 D3 keeps out of the enforcement path.
+
+The vocabulary is therefore closed to the four framework-owned names:
+`owner` / `admin` / `delegated_admin` / `member`.
+
+**BREAKING — `additionalOrgRoles` is removed** from `AuthManagerOptions` and
+`AuthPluginOptions`, together with `plugin-auth/src/org-roles.ts` in full
+(`collectStackOrgRoles`, `collectRegisteredOrgRoles`,
+`normalizeAdditionalOrgRoles`, `membershipRoleOptions`,
+`withMembershipRoleOptions`, `membershipRoleLabel`, `orgRoleNames`,
+`MEMBERSHIP_ROLE_OBJECTS`, `OrgRoleDescriptor`, `OrgRoleInput`,
+`OrgRoleLogger`) and the `kernel:ready` derivation hook that fed them. From
+`@objectstack/spec`, `MEMBERSHIP_ROLE_NAME_PATTERN` and
+`MEMBERSHIP_ROLE_NAME_MIN_LENGTH` are removed — they existed only to validate
+app-supplied names. A TypeScript error is the intended failure: an option that
+is silently ignored is `declared ≠ enforced` one more time.
+
+FROM → TO:
+
+```diff
+- new AuthPlugin({ additionalOrgRoles: ['sales_rep'] })
++ new AuthPlugin({ /* nothing — declare `sales_rep` as a position */ })
+
+- POST /organization/invite-member { email, role: 'sales_rep' }
++ POST /organization/invite-member { email, role: 'member',
++                                    businessUnitId, positions: ['sales_rep'] }
+```
+
+For an existing member, assign the position through `sys_user_position` (the
+governed write path). Invitation placement (ADR-0105 D8) is the one-step
+admission flow: issuance is authorized against the issuer's `adminScope` by
+dry-running `DelegatedAdminGate`, and acceptance writes real
+`sys_user_position` rows with a `granted_by` stamp. It reaches **further** than
+what it replaces — a delegated admin may use it within their subtree, where the
+membership-role route was open to org admins only (the invitation role cap holds
+anyone below admin grade to plain `member`).
+
+An invitation naming an app role now fails at better-auth's door with
+`ROLE_NOT_FOUND`, before any row is written.
+
+This reverses two changesets that were never consumed into a release
+(`app-org-roles-storable`, `auth-org-roles-self-derived`), so no published
+version ever offered the behaviour; both are removed rather than shipped and
+retracted in the same changelog. A pre-existing deployment could only have
+stored a custom value by direct DB write.
+
+Also derived rather than transcribed: `@objectstack/lint`'s `MEMBERSHIP_TIERS`
+now reads `BUILTIN_MEMBERSHIP_ROLES` from `@objectstack/spec`. The hand-kept
+copy carried `guest`, which the `sys_member.role` select has never offered — an
+approver authored as `{ type: 'org_membership_level', value: 'guest' }`
+resolved to nobody and the lint whose whole job is to catch that stayed silent.

.changeset/auth-org-roles-self-derived.md

@@ -668,39 +668,52 @@ new AuthPlugin({
 })
 ```
 
-#### Positions as membership tiers
+#### Membership tiers are a closed list
 
 `sys_member.role` is better-auth's own column and the one place ObjectStack
-keeps that vocabulary (ADR-0090 D3's single boundary exception). Beyond the
-four built-in tiers — `owner`, `admin`, `delegated_admin`, `member` — every
-[position](/docs/permissions/positions) and
-[permission set](/docs/permissions/permission-sets) your stack declares is
-registered as a valid value, so an invitation can name one directly:
+keeps that vocabulary (ADR-0090 D3's single boundary exception). It holds
+exactly four values — `owner`, `admin`, `delegated_admin`, `member` — and your
+stack cannot add to them.
+
+That is deliberate (ADR-0108). A membership tier answers *what is your standing
+in this organization*, which decides what you can **reach**: `delegated_admin`,
+for instance, is the tier that may reach `/organization/invite-member` without
+being an org admin. What you may **do** with records is a
+[position](/docs/permissions/positions), and every position assignment carries
+an audit stamp (`granted_by`), a validity window, and a scope check that a tier
+never had.
+
+To invite someone straight into a position, put it in the invitation's
+*placement* rather than its membership tier:
 
 ```http
 POST /api/v1/auth/organization/invite-member
-{ "email": "new.hire@example.com", "role": "sales_rep" }
+{
+  "email": "new.hire@example.com",
+  "role": "member",
+  "businessUnitId": "bu_field_sales",
+  "positions": ["sales_rep"]
+}
 ```
 
-On acceptance the value lands in `sys_member.role`, and the membership
-projection passes an unrecognized value through as a position name — so the
-invitee holds `sales_rep` in `current_user.positions` and resolves whatever
-permission sets are bound to it. Both `sys_invitation` and `sys_member` build
-their pickers from that same registered set, so the Setup UI offers your names
-alongside the built-ins.
-
-Two limits bound this as a provisioning path:
-
-- **It never hands out more authority than the issuer has.** An issuer below
-  `admin` grade may invite as plain `member` only, and no invitation may confer
-  a tier above the issuer's own. A delegated admin grants capability through
-  the invitation's *placement* (business unit + positions), authorized against
-  their `adminScope` — not through the membership tier, which nothing scopes.
-- **Only spec-compliant names are registered.** A declared name that is not
-  lowercase snake_case (`/^[a-z][a-z0-9_]*$/`, minimum 2 characters) is skipped
-  with a boot warning, and an invitation naming it is refused with
-  `ROLE_NOT_FOUND` — better-auth never learns a name the write path could not
-  store.
+The tier stays `member`; the capability rides in `positions`. Placement is
+authorized at issuance against the issuer's `adminScope`, so a delegated admin
+can use it inside their own subtree — where the tier route was open to org
+admins only. On acceptance the positions become real `sys_user_position` rows.
+
+<Callout type="warn">
+Earlier releases registered every declared position and permission-set name as
+a valid membership tier, so naming one directly in the invitation was accepted.
+That path is removed: because every value stored in the tier column is
+projected into `current_user.positions`, it granted capability with none of the
+controls above. Naming a position as an invitation's tier is now refused with
+`ROLE_NOT_FOUND`. Use `positions` as shown.
+</Callout>
+
+One limit still bounds invitations as a provisioning path: **they never hand out
+more authority than the issuer has.** An issuer below `admin` grade may invite
+as plain `member` only, and no invitation may confer a tier above the issuer's
+own.
 
 ### Admin User Management
 

.changeset/membership-grade-not-capability-channel.md

@@ -173,10 +173,12 @@ issuance:
 - an invited role may not outrank the issuer's (`owner` > `admin` > everyone
   else);
 - an issuer below admin grade may invite as **`member` only**. Not just "not
-  admin/owner": an app-registered role projects into `current_user.positions`
-  and may be bound to permission sets, so it is a capability channel too. A
-  delegate's channel for capability is the invitation's **placement** intent,
-  which this gate allowlists position-by-position;
+  admin/owner": every value stored in `sys_member.role` projects into
+  `current_user.positions`, so any tier above plain member is a capability
+  channel too. A delegate's channel for capability is the invitation's
+  **placement** intent, which this gate allowlists position-by-position — and
+  since ADR-0108 that is the *only* way capability travels on an invitation,
+  because the tier vocabulary is closed to four framework-owned names;
 - an issuer whose membership cannot be read confers nothing above a plain
   member (fail-closed).
 

content/docs/permissions/authentication.mdx

@@ -16,10 +16,12 @@ of their own** — they only decide *who gets which sets*.
 > security identifiers and labels). The vocabulary is now unambiguous:
 > **permission set** = capability, **position** = distribution,
 > **business unit** = hierarchy. The single exception is better-auth's
-> internal `sys_member.role` — the org-membership tier (`owner`, `admin`,
-> `delegated_admin`, `member`, **plus every position name your stack
-> declares**, so a person can be invited straight into a position; see
-> [Authentication](/docs/permissions/authentication#positions-as-membership-tiers)).
+> internal `sys_member.role` — the org-membership tier, a **closed** list of
+> `owner`, `admin`, `delegated_admin`, `member` and nothing else (ADR-0108). A
+> tier decides what you can *reach*; a position decides what you may *do*. To
+> invite someone straight into a position, use the invitation's `positions`
+> placement, not its membership tier — see
+> [Authentication](/docs/permissions/authentication#membership-tiers-are-a-closed-list).
 
 ```typescript
 import type { Position } from '@objectstack/spec/identity';