fix(plugin-security,spec): PERMISSION_DENIED stops showing developer copy to end users (#7414)

The 403 refusal is correct and its transport is fine; the message was not.
`Error.message` is the body's human-readable string on every transport and
Console renders it verbatim in a toast, so a business user in a localized app
got an English sentence naming an object API name they had never seen and
ending in `positions [org_member, everyone]`.

The error now carries two messages because it has two audiences:

- `message` — the user's half, rendered in `ExecutionContext.locale` through
  the SHARED operation-message catalog #7307 built (`errors.permission_denied`).
  It names no object, no operation and no position, in any shipped locale.
- `developerMessage` — the developer's half, the previous sentence byte for
  byte. LOGGED at the throw site rather than shipped: unlike the 409, this
  body carries no structured API names, so shipping it would have added a
  disclosure instead of removing one. It is a sibling of `details`, never a
  member of it, because `details` is what the dispatcher serialises.

`code` / `statusCode` / `details` unchanged; one PERMISSION_DENIED (ADR-0112),
two sentences.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BM1tNf5U3nEbHKR4fo5qVQ

Author: claude

.changeset/permission-denied-user-copy.md

@@ -0,0 +1,50 @@
+---
+"@objectstack/spec": minor
+"@objectstack/plugin-security": minor
+---
+
+fix(plugin-security,spec): the `403 PERMISSION_DENIED` from the object CRUD gate stops handing a business user internal authorization vocabulary
+
+An operation the caller's permission sets do not grant is correctly refused with
+`403 PERMISSION_DENIED`, and the transport was never the problem. What reached
+the end user was: `Error.message` is the body's human-readable string on every
+transport (`mapDataError`'s `body.error`, the dispatcher's `error.message`) and
+Console renders it verbatim in a toast. So an operator in a fully localized app
+read
+
+```
+[Security] Access denied: operation 'delete' on object 'app_child_object'
+is not permitted for positions [org_member, everyone]
+```
+
+English-only; naming a table they have never seen; ending in `positions [...]`,
+internal authorization vocabulary that reads as a contradiction to someone who
+does hold rights on the record they clicked. It is not confined to obviously
+unauthorized actions either — `cascadeDeleteRelations` re-authorises every
+cascade CHILD independently, so an ordinary delete of a parent the app
+deliberately granted can surface a 403 naming a child object the operator never
+addressed.
+
+The error now carries two messages because it has two audiences:
+
+- `message` — the user's half, rendered in `ExecutionContext.locale` through the
+  shared operation-message catalog (`@objectstack/spec/system`, the mechanism
+  built for `DELETE_RESTRICTED`), overridable per deployment under
+  `errors.permission_denied`. It names no object, no operation and no position,
+  in any of the four shipped locales.
+- `developerMessage` — the developer's half, the previous sentence byte for
+  byte. It is LOGGED at the throw site, not shipped to the client.
+
+That last point is where this deliberately diverges from its sibling.
+`DELETE_RESTRICTED` ships its developer half over the wire because the same body
+already carries the API names it mentions; the 403 body does not. REST's
+`mapDataError` builds `{ error, code, object? }` for a permission denial and
+never reads `error.details`, so the positions, the operation and (on a cascade)
+the child object's API name reach a client through nothing but the message —
+shipping a `developerMessage` there would have ADDED a disclosure rather than
+removed one. `developerMessage` is therefore a sibling of `details`, never a
+member of it, because `details` is the field the runtime dispatcher serialises.
+
+Enforcement is untouched: same 403, same `PERMISSION_DENIED`, same decision
+logic, and the structured `details` payload (`operation`, `object`, `positions`,
+`permissionSets`) is byte-identical to before.

packages/plugins/plugin-security/package.json

@@ -26,6 +26,7 @@
   "devDependencies": {
     "@objectstack/metadata-core": "workspace:*",
     "@objectstack/plugin-sharing": "workspace:*",
+    "@objectstack/service-i18n": "workspace:*",
     "@types/node": "^26.1.2",
     "typescript": "^6.0.3",
     "vitest": "^4.1.10"

packages/plugins/plugin-security/src/errors.ts

@@ -4,15 +4,40 @@
  * Typed sentinel error thrown by `SecurityPlugin` when an operation is
  * denied. Caught by `@objectstack/runtime`'s HTTP dispatcher and translated
  * to HTTP 403.
+ *
+ * ## Two messages, two audiences (#7414)
+ *
+ * `message` is what an END USER reads: both transports ship it verbatim as the
+ * body's human-readable string (`mapDataError`'s `error`, the dispatcher's
+ * `error.message`) and Console renders it as-is in a toast. `developerMessage`
+ * is the operator's half — English, API names, the authorization vocabulary
+ * that explains WHY — and it is the throw site's job to route it somewhere a
+ * developer reads.
+ *
+ * ⛔ `developerMessage` is a sibling of `details`, deliberately NOT a member of
+ * it. `details` is SERIALISED to the client on the dispatcher transport
+ * (`http-dispatcher.ts`: `this.error(e.message, 403, { code, ...e.details })`,
+ * which `buildApiError` puts on the wire as `error.details`), so anything
+ * placed inside it reaches the browser. A developer sentence that names
+ * positions and permission sets must not travel that way — see the throw site
+ * in `security-plugin.ts` and the measurement recorded in
+ * `permission-denied-user-copy.test.ts`.
  */
 export class PermissionDeniedError extends Error {
   readonly code = 'PERMISSION_DENIED';
   readonly statusCode = 403;
   readonly details?: Record<string, unknown>;
-  constructor(message: string, details?: Record<string, unknown>) {
+  /**
+   * The operator-facing half of a refusal whose `message` has been localized
+   * for an end user. Optional: a denial that never localized its message has
+   * exactly one audience and carries none.
+   */
+  readonly developerMessage?: string;
+  constructor(message: string, details?: Record<string, unknown>, developerMessage?: string) {
     super(message);
     this.name = 'PermissionDeniedError';
     this.details = details;
+    if (developerMessage !== undefined) this.developerMessage = developerMessage;
   }
 }