@@ -0,0 +1,34 @@
+---
+'@objectstack/spec': minor
+'@objectstack/plugin-security': minor
+'@objectstack/rest': minor
+---
+
+feat(plugin-security,rest,spec)!: the permission-set "Discard Overlay" action, its REST route and its contract member are retired; no door creates the overlay it discarded, and a database holding one is refused at cold boot (ADR-0131 cutover, ADR-0048)
+
+Clause-②: no (narrowing)
+
+<!-- adr-0087: registered security-permission-set-overlay-discard-retired -->
+
+**BREAKING** — a narrowing of the public surface: one HTTP route, one Setup action and one optional contract member are removed. Shipped as `minor` under the launch-window convention for breaking changes.
+
+The action deleted the environment-wide `sys_metadata` row that shadowed a package-declared permission set, then re-projected the set's `sys_permission_set` row. Neither half has anything left to do:
+
+- No door creates such an overlay. The metadata door refuses a save over a packaged permission set on every topology, whatever `OS_METADATA_WRITABLE` says. The data door refuses an edit of one (clone it instead). The data API cannot write `sys_metadata`. A package that declares a name the environment holds is refused at install.
+- An overlay stored before those refusals makes the cold boot refuse the deployment with `422 NAMESPACE_CONFLICT`, so a server that could answer the route never holds one.
+- The authorization resolver reads the security catalog, not `sys_permission_set` rows, so the re-projected row granted nothing.
+
+### What was removed
+
+| removed | what to use instead |
+| --- | --- |
+| `POST /api/v1/security/permission-sets/:id/discard-overlay` | `os migrate security-catalog-overlays` with the flags and environment the deployment boots with lists every overlay row with no server running; `--apply` deletes them (a history tombstone per row). |
+| the **Discard Overlay** action on `sys_permission_set` in Setup | the same offline step. To keep a customization of a packaged set, clone it under a new name (the **Clone** action) and assign the clone. |
+| `ISecurityService.discardPermissionSetOverlay` and `PermissionSetOverlayDiscardResult` (`@objectstack/spec/contracts`) | nothing: delete the call and the import. `tsc` names each one. |
+| `discardPermissionSetOverlay`, `PermissionSetNotFoundError`, `PermissionSetOverlayStateError` and the `PermissionSetOverlayDiscardDeps` / `PermissionSetOverlayDiscardResult` types (`@objectstack/plugin-security`) | nothing: delete the import. |
+
+**The one-line fix:** stop calling the route or the member, and clear any overlay offline with `os migrate security-catalog-overlays --apply` before the first boot on this release.
+
+`ERROR_CODE_LEDGER['@objectstack/plugin-security']` no longer lists `INVALID_STATE` or `NOT_FOUND`: the removed action was their only producer in this package. Both codes stay registered under `@objectstack/rest`, and the union of codes is unchanged.
+
+The permission-set drift diagnostic no longer names the action in its `overlay_shadow` detail, and the boot reading of shadowed packaged sets names the offline step instead.
@@ -144,7 +144,7 @@ A permission set and a position also have a switch, outside the refusal: `POST /
 
 The switches are operator-only where one install serves several organizations. The refusal names the same path whichever layer answers it: `403 NOT_OVERRIDABLE` for a write that names no base, and `403 ITEM_LOCKED` for one that names the read-only package. Which writes are refused, and with which code, is unchanged.
 
-An environment row stored over a managed item of a type sealed against overlays (a flow, action, hook, object or datasource, for example — any type whose registry entry admits no overlay) before the seal — written through the `OS_METADATA_WRITABLE` hatch — is **not served** (ADR-0131 D6): every read, and boot, takes the package's definition, and the row stays at rest, untouched. Boot names each such row, per type (`[metadata_sealed_overlay_unserved]`), with the two remedies: re-express the change as a new item under a new name, or delete the stored row. A stored fork of a code-declared permission set is the one exception: it keeps the detection reading and the operator's Discard Overlay action it already had.
+An environment row stored over a managed item of a type sealed against overlays (a flow, action, hook, object or datasource, for example — any type whose registry entry admits no overlay) before the seal — written through the `OS_METADATA_WRITABLE` hatch — is **not served** (ADR-0131 D6): every read, and boot, takes the package's definition, and the row stays at rest, untouched. Boot names each such row, per type (`[metadata_sealed_overlay_unserved]`), with the two remedies: re-express the change as a new item under a new name, or delete the stored row. A stored fork of a code-declared permission set is the one exception: the deployment does not boot while it holds one (ADR-0048), and `os migrate security-catalog-overlays` lists and, with `--apply`, deletes it.
 
 ---
 
 
@@ -306,7 +306,7 @@ that bypassed write hooks, `rebuildSearchCompanion` (from
 | `OS_MARKETPLACE_CACHE` | enum | `on` | `off` disables the in-memory marketplace listing cache. |
 | `OS_MARKETPLACE_PUBLIC_BASE_URL` | url | — | Public base URL of the marketplace registry (proxied from this runtime when set). |
 | `OS_ALLOW_UNMASKED_OBJECT_METADATA` | boolean | `false` | Escape hatch for the metadata-plane field-level security mask ([ADR-0106](https://github.com/objectstack-ai/objectstack/blob/main/docs/adr/0106-metadata-plane-fls-object-schema-masking.md) D8). By default every object schema served by `/meta` and `/metadata` is projected onto the fields the **calling user** may read, so a field they cannot read does not appear at all — not its name, label, type, picklist options, formula, `visibleWhen` predicate, `defaultValue`, or the `requiredPermissions` capability guarding it. Set to `1` to serve the full schema to every authenticated caller, as releases before this one did. This changes **disclosure only**: the data plane still masks values and refuses forbidden writes either way, and the console reads field affordances from `/auth/me/permissions`, so toggling it never changes UI correctness. The REST layer also honours a per-server `metadata.maskObjectFields: false`; this variable is the deployment-wide knob and covers the runtime `/metadata` dispatcher, which has no REST config to read. |
-| `OS_METADATA_WRITABLE` | csv | — (none) | Comma-separated metadata type names (e.g. `hook,job`) granted a runtime escape hatch that treats them as `allowOrgOverride: true` for items **no managed package ships**: it opens runtime creation of a type whose registry entry allows none. It never opens an organization-scoped write: since [ADR-0131](https://github.com/objectstack-ai/objectstack/blob/main/docs/adr/0131-total-organization-ownership-no-null-organization-id.md) D6 the metadata protocol refuses every organization-scoped write with `403 NOT_OVERRIDABLE`. It **never opens an item a managed package ships**: managed content is sealed ([ADR-0131](https://github.com/objectstack-ai/objectstack/blob/main/docs/adr/0131-total-organization-ownership-no-null-organization-id.md) D6), so an overlay or a removal of a shipped flow, object, field, permission set, position or any other type without an environment overlay is refused with `403 NOT_OVERRIDABLE` whether the hatch is set or not. Customize managed content through its type's own route instead: an environment overlay for `view`, `dashboard`, `report`, `translation` and `email_template`; disable, or clone under a new name, for a flow; clone for a permission set. An overlay row this hatch wrote before over a managed item is kept at rest but **not served**: every read takes the package's definition, and boot names each such row, per type (`[metadata_sealed_overlay_unserved]`), with the two remedies — re-express the change as a new item under a new name, or delete the row. A stored fork of a packaged permission set is the one exception: it is still served, with its detection reading and Discard Overlay. Removing that permission-set row restores the package's definition. A stored row over a managed item of the other types that merge overlays at read (`position`, `page`, `app`, `dataset`, `book`, `tool`, `skill`) can still be removed, but removing it changes nothing that is served: no read serves it, so the package's definition is already served. See [ADR-0005](https://github.com/objectstack-ai/objectstack/blob/main/docs/adr/0005-metadata-customization-overlay.md). |
+| `OS_METADATA_WRITABLE` | csv | — (none) | Comma-separated metadata type names (e.g. `hook,job`) granted a runtime escape hatch that treats them as `allowOrgOverride: true` for items **no managed package ships**: it opens runtime creation of a type whose registry entry allows none. It never opens an organization-scoped write: since [ADR-0131](https://github.com/objectstack-ai/objectstack/blob/main/docs/adr/0131-total-organization-ownership-no-null-organization-id.md) D6 the metadata protocol refuses every organization-scoped write with `403 NOT_OVERRIDABLE`. It **never opens an item a managed package ships**: managed content is sealed ([ADR-0131](https://github.com/objectstack-ai/objectstack/blob/main/docs/adr/0131-total-organization-ownership-no-null-organization-id.md) D6), so an overlay or a removal of a shipped flow, object, field, permission set, position or any other type without an environment overlay is refused with `403 NOT_OVERRIDABLE` whether the hatch is set or not. Customize managed content through its type's own route instead: an environment overlay for `view`, `dashboard`, `report`, `translation` and `email_template`; disable, or clone under a new name, for a flow; clone for a permission set. An overlay row this hatch wrote before over a managed item is kept at rest but **not served**: every read takes the package's definition, and boot names each such row, per type (`[metadata_sealed_overlay_unserved]`), with the two remedies — re-express the change as a new item under a new name, or delete the row. A stored fork of a packaged permission set is the one exception: the deployment does not boot while it holds one (ADR-0048); `os migrate security-catalog-overlays` lists such rows and, with `--apply`, deletes them, which restores the package's definition. A stored row over a managed item of the other types that merge overlays at read (`position`, `page`, `app`, `dataset`, `book`, `tool`, `skill`) can still be removed, but removing it changes nothing that is served: no read serves it, so the package's definition is already served. See [ADR-0005](https://github.com/objectstack-ai/objectstack/blob/main/docs/adr/0005-metadata-customization-overlay.md). |
 
 ---
 
 
@@ -382,15 +382,13 @@ either can be live on one row, and they need different remedies:
   (from a Studio save made while overlaying was still permitted, or through
   the `OS_METADATA_WRITABLE` escape hatch) is re-projected onto the record on
   every boot, unconditionally — the overlay wins forever, regardless of what
-  the package ships next. **Remedy:** the record's **Discard Overlay** Setup
-  action (`POST /api/v1/security/permission-sets/:id/discard-overlay`,
-  tenant-admin only) removes the stale overlay and resyncs the record to the
-  current artifact immediately. It refuses on any set that no installed code
-  package ships (a set created in this environment, a clone, or a set saved
-  into a writable runtime package), so it can never destroy a genuinely
-  environment-authored set. **Discard it before you upgrade:** from the
+  the package ships next. No door creates such an overlay any more: the
+  metadata door refuses a save over a packaged set, and so does the data door
+  (clone the set instead). **Remedy:** delete the overlay row. From the
   release that adds ADR-0048's cold-boot check, a deployment that still holds
-  such an overlay does not boot, so the action can no longer reach it.
+  one does not boot: `os migrate security-catalog-overlays` lists every such
+  row with no server running, and `--apply` deletes them, after which the
+  package's definition is served again.
 - **Provenance skip.** The record's `managed_by` column predates package
   provenance tracking (a legacy insert without `managed_by: 'package'` —
   typically a database first initialized on an older release line), so boot
 
@@ -10,7 +10,7 @@ the seed loader replaying package fixtures, a plugin's boot reconciler, a
 service self-write, a migration.
 
 This page is **the authority** for what that flag actually does. It exists
-because the flag is not one concept: it is a single boolean read at **123
+because the flag is not one concept: it is a single boolean read at **122
 distinct sites across 20 packages**, and knowing three of those behaviours gives
 no hint that the other hundred-and-four exist. Every documented app-side bug
 traced to `isSystem` had the same shape — the metadata was complete and correct,
@@ -112,7 +112,6 @@ that silently does not happen.
 | 11b | Position write-through skipped — a `sys_position` write is not mirrored into the environment ledger | plugin-security | Get: the seeders and the package door write rows for definitions that already have their home, untouched. Lose: a system-written row has no environment definition, so the security catalog read does not resolve it until a data-door edit, or the one-time row-only position backfill, gives it one | `packages/plugins/plugin-security/src/position-write-through.ts#createPositionWriteThrough` |
 | 12 | Session-resolution middleware skipped | plugin-auth | Get: no session lookup attempted | `packages/plugins/plugin-auth/src/auth-plugin.ts#start` |
 | 13 | Per-request performance timings disclosed | observability | Get: timing headers a normal caller cannot pull | `packages/observability/src/perf-timing.ts#isPerfDisclosurePrincipal` |
-| 14 | Permission-set **overlay discard** skips the tenant-admin assertion | plugin-security | Get: an overlay can be discarded with no authenticated tenant administrator | `packages/plugins/plugin-security/src/permission-set-overlay-discard.ts#assertTenantAdmin` |
 | 15 | MCP stdio bridge skips the object API-exposure gate | mcp | Get: the bridge reaches objects whose `apiEnabled` / `apiMethods` would refuse an external caller | `packages/mcp/src/stdio-data-bridge.ts#enforceApiExposure` |
 | 16 | **Read-audit rows are not written** | plugin-audit | Lose: the "a person opened this record" trail. `sudo()` keeps the caller's `userId`, so this flag is the only thing separating a human read from a platform one | `packages/plugins/plugin-audit/src/read-audit.ts#installReadAuditWriter` |
 | 17 | Approval snapshot payload redaction skipped, and so is the snapshot query guard | plugin-approvals | Get: the whole snapshot on `find` / `findOne` — the audit/replay channel — and a filter, sort or grouping by it on any read. Lose: field-visibility redaction over approval payloads, and the refusal of a query over the snapshot for a reader withheld a field of the objects it can reach | `packages/plugins/plugin-approvals/src/payload-redaction-middleware.ts#bindSnapshotRedactionMiddleware`, `packages/plugins/plugin-approvals/src/payload-predicate-guard.ts#bindSnapshotPredicateGuard` |
@@ -143,7 +142,7 @@ that silently does not happen.
 
 ### 3. Sharing (`plugin-sharing`)
 
-The largest single consumer — **17 of the 123 sites**.
+The largest single consumer — **17 of the 122 sites**.
 
 | # | Behaviour when `isSystem` | What you get / what you lose | Anchor |
 |:--|:---|:---|:---|
@@ -286,7 +285,7 @@ Ownership injection, `readonly` bypass and sharing materialisation are
 independent decisions, and a seed loader plausibly wants the first two but not
 the third. The concept is nevertheless **staying as one boolean**:
 
-- **Shipped semantics.** `isSystem` is a published contract with 123 read sites
+- **Shipped semantics.** `isSystem` is a published contract with 122 read sites
   in 20 packages. Splitting it is a breaking contract change across all of them.
   (The ruling was taken when the census read 80 sites in 18 packages; the count
   has grown, which strengthens rather than weakens the argument.)
@@ -360,16 +359,16 @@ still holds equal to the census on every pull request:
 | Appearances of the bare identifier `isSystem` in non-test sources | 813 | — |
 | — parsed as a declaration | 28 | ✅ |
 | — parsed as an object-literal / type key (producers and option objects) | 310 | — |
-| — parsed as a property **read** | 129 | ✅ |
+| — parsed as a property **read** | 128 | ✅ |
 | — parsed in some other syntactic position (a local, a cast, a conditional) | 9 | ✅ |
 | — the remainder: text inside comments and string literals | 358 | — |
 | Of those reads: reads of one of the unrelated metadata fields | 6 | ✅ |
-| Of those reads: reads of `ExecutionContext.isSystem` | **123** | ✅ |
-| — behaviour-bearing (rows 1–61 above) | 120 | ✅ |
+| Of those reads: reads of `ExecutionContext.isSystem` | **122** | ✅ |
+| — behaviour-bearing (rows 1–61 above) | 119 | ✅ |
 | — carry the flag onward only (rows 62–64 above) | 3 | ✅ |
 | Packages containing at least one elevation read | **20** | ✅ |
-| Files containing at least one elevation read | 58 | ✅ |
-| — the distinct symbols those reads live in — what this page anchors | 105 | ✅ |
+| Files containing at least one elevation read | 57 | ✅ |
+| — the distinct symbols those reads live in — what this page anchors | 104 | ✅ |
 | — of those files, the ones holding more than one read in one symbol | 8 | ✅ |
 
 The six rows marked — are a **dated decomposition, not a live claim**: they were
@@ -433,7 +432,7 @@ same resolver, and the same registration shape, that holds `docs/adr/**`.
 Renaming a symbol is now a loud red instead of a silent misdirection.
 
 ⚠️ **The precision that costs, priced here rather than buried.** A symbol anchor
-cannot say WHICH read inside a function it means, and **8** of the **58**
+cannot say WHICH read inside a function it means, and **8** of the **57**
 anchored files hold more than one read inside a single symbol. So the population
 check runs per file at symbol granularity: every file the census finds a read in
 must be anchored, and the set of symbols this page cites into that file must