fix(sharing,approvals,runtime,security): platform authority is the posture RUNG, never a name in positions[]

.changeset/positions-name-is-not-platform-authority.md

@@ -0,0 +1,21 @@
+---
+"@objectstack/plugin-sharing": patch
+"@objectstack/plugin-approvals": patch
+"@objectstack/plugin-security": patch
+"@objectstack/runtime": patch
+---
+
+Four server-side authorization sites stop deriving platform-operator authority from a NAME in `ExecutionContext.positions`, and read the ADR-0095 posture rung instead.
+
+`positions[]` is the security axis, so it carries ADR-0057 D4 `sys_user_position` names alongside the built-ins. `sys_user_position` is `apiEnabled` and its `position` values are unconstrained, so a tenant could mint a row spelling `platform_admin` for one of their own users: `resolveUserAuthzGrants` pushed that name straight onto `grants.positions`, while `grants.posture` — derived from the unscoped `admin_full_access` grant and nothing else — correctly stayed `MEMBER`. Every reader of the name therefore answered `true` for a principal enforcement treats as an ordinary member. `resolve-authz-context.ts` states the rule at `hasPlatformAdminStanding` ("read the RUNG — never `positions.includes(...)`"), but a comment is not a gate and these four had not followed it.
+
+Each site now tests `posture === 'PLATFORM_ADMIN'`, byte-for-byte what `hasPlatformAdminStanding` returns:
+
+- **`plugin-sharing`** — `hasPlatformAuthority`. The minted row satisfied `assertResolvableAdminScope`, so an org-less caller holding only the ORG-scoped `manage_sharing` capability was answered with **every tenant's** sharing rules, and could delete platform-global rules. The `manage_platform_settings` capability spelling is unchanged.
+- **`plugin-approvals`** — `isOverrideActor`. This predicate already read the rung and then ORed the name onto it, which is no protection: an OR is only as strong as its weakest arm. Because the platform arm deliberately crosses the tenant wall, the minted row let a member of one organization approve, reject or recall a **different organization's** pending request while holding no slot in its slate. The `ADMIN_FULL_ACCESS` capability arm and both TENANT_ADMIN arms are unchanged.
+- **`runtime`** — the ADR-0126 §5 activation gate. Under a `group` or `isolated` posture this gate is the only thing between a tenant org admin and the **install-wide** `sys_metadata_activation` row, so the minted row reopened #10243 with a durable row behind it.
+- **`plugin-security`** — `derivePosture` in the explain engine. Narrower than the other three, and stated precisely rather than overclaimed: the name-read sat behind an early `ctx.posture` return that `buildContextForUser` always populates, so the shipping path was already gated and a D4 row never moved it. What the read did reach was a posture-less hand-built context, where it made the panel **report** `PLATFORM_ADMIN` for a principal enforcement treats as a MEMBER — a misreport rather than an admission, but in the one tool an administrator opens to check exactly this.
+
+No behaviour changes for a genuine platform operator: their resolved context carries the rung, and the built-in position is still projected onto `positions[]` for display and predicate use. What changes is that the name alone no longer answers the authorization question.
+
+Graded `patch` on the surface it moves: no exported type, signature or contract changes, and no authorable metadata is added, removed or renamed. The only observable difference is that a principal who never held the capability grant stops being admitted — which is the defect, not a feature anyone could have depended on.

content/docs/permissions/system-context.mdx

@@ -137,15 +137,15 @@ The largest single consumer — **17 of the 105 sites**.
 | 36 | `sys_record_share` reads are **not** self-scoped | Get: tenant-wide share listing without `manage_sharing` | `sharing-plugin.ts:1189` |
 | 37 | Share-link policy `enabled` check bypassed; system callers re-enter under a system context | Get: link **creation** while the policy is off — resolution is **not** bypassed since #14033 (`publicSharing.enabled` is a standing policy held at every redemption): a link minted this way does not resolve until the block is enabled | `plugin-sharing/src/share-link-service.ts:459`, `:513`, `:517`, `:590`, `:620` |
 | 38 | Sharing-rule provenance stamp skipped | Lose: the row is not marked as an admin customization — seeder / `defineRule` / boot reconcilers are "the package door" | `sharing-rule-provenance.ts:66` |
-| 39 | Sharing-rule service write + delete paths return early | Lose: the manage-rules gate on the service surface, and the platform-global-rule delete guard | `sharing-rule-service.ts:278`, `:503` |
+| 39 | Sharing-rule service write + delete paths return early | Lose: the manage-rules gate on the service surface, and the platform-global-rule delete guard | `sharing-rule-service.ts:279`, `:518` |
 
 ### 4. Approvals, reports, attachments, comments, knowledge
 
 | # | Behaviour when `isSystem` | Package | What you get / what you lose | Anchor |
 |:--|:---|:---|:---|:---|
 | 40 | **Approval record lock released** — a locked record is writable | plugin-approvals | Get: engine self-writes (the status mirror) pass. Lose: the lock that stops edits while an approval is live. Note there is deliberately **no admin exemption** here — only `isSystem` | `lifecycle-hooks.ts:347` |
 | 41 | Delegation write guard bypassed | plugin-approvals | Get: service / seed / import may write delegation rows naming another delegator | `lifecycle-hooks.ts:570` |
-| 42 | Approval actor / submitter / pending-approver checks bypassed (8 sites) | plugin-approvals | Get: approve, reject, recall, reassign without being a pending approver or the submitter | `plugin-approvals/src/approval-service.ts:1093`, `:1202`, `:3458`, `:3606`, `:3774`, `:3845`, `:4034`, `:4074` |
+| 42 | Approval actor / submitter / pending-approver checks bypassed (8 sites) | plugin-approvals | Get: approve, reject, recall, reassign without being a pending approver or the submitter | `plugin-approvals/src/approval-service.ts:1096`, `:1219`, `:3475`, `:3623`, `:3791`, `:3862`, `:4051`, `:4091` |
 | 43 | Saved-report ownership is **assignable**, and an update may reassign it | plugin-reports | Get: `ownerId` from input is honoured. A non-system caller always owns what it creates and can never reassign | `plugin-reports/src/report-service.ts:404`, `:425` |
 | 44 | Saved-report access / export / mutation gates bypassed | plugin-reports | Get: read, bulk-export and overwrite any report | `plugin-reports/src/report-service.ts:343`, `:372`, `:447`, `:684` |
 | 45 | Attachment access hooks return early (insert + update + delete, and the read AST) | service-storage | Lose: attachment visibility scoping | `attachment-access-hooks.ts:300`, `:349`, `:448`, `:524` |
@@ -164,7 +164,7 @@ The largest single consumer — **17 of the 105 sites**.
 | 53 | MCP principal check satisfied | runtime | Get: MCP surface reachable with no user | `domains/mcp.ts:61` |
 | 54 | Package REST route capability gate bypassed | rest | Get: package read/write over REST without `manage_metadata` / `studio.access` / `setup.access` | `package-routes.ts:102` |
 | 55 | Package domain capability gates bypassed | runtime | Get: package management and package-inventory reads without the capability | `domains/packages.ts:241`, `:274` |
-| 56 | Activation write / authoring refusals do not fire | runtime | Get: activation artifacts writable and authorable without the activation-authoring capability | `activation-gate.ts:138`, `:189` |
+| 56 | Activation write / authoring refusals do not fire | runtime | Get: activation artifacts writable and authorable without the activation-authoring capability | `activation-gate.ts:157`, `:211` |
 | 57 | Automation run-state read, flow-authoring write and unrelated-screen read all pass | runtime | Get: run state, flow writes and screen reads with no grant | `domains/automation.ts:254`, `:545`, `:635` |
 | 58 | Audience-binding suggestion recording skipped | plugin-security | Lose: install-time suggestions are not recorded for system callers | `suggested-audience-bindings.ts:703` |
 | 59 | Email-template / webhook provenance stamps skipped | plugin-email, plugin-webhooks | Lose: the row is not marked as an admin customization | `email-template-provenance.ts:77`, `webhook-provenance.ts:68` |