chore(changeset): record the plugin-security default-permission-set reader correction (#15298)

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UHvF5hyiZjnCyExFnfQB8m

Author: claude

.changeset/plugin-security-default-set-answer-not-container.md

@@ -0,0 +1,50 @@
+---
+"@objectstack/plugin-security": patch
+---
+
+fix(plugin-security): the app default permission set resolves from the first level that NAMES one (#15298)
+
+`declaredPermissionSets` carried a docblock stating a short-circuit its code did
+not have:
+
+> The `packages[]` pass only supplies a set where the top level had none — which
+> is precisely the option-B artifact.
+
+The code pushed the flattened top level and then **every** package body
+unconditionally, so on today's additive artifact (flattened level *and*
+`packages[]` both present) every permission set was collected twice. Nothing
+observable came of it — the sole caller is private and takes the first
+`isDefault` set, which the flattened copy still supplied — so this corrects a
+false written contract on a security-path reader, not a live defect. That
+distinction is the point: the sentence was load-bearing, because it was the
+stated reason the reader half was revertible on its own and safe to land before
+the emitter half (#14512), and the next reader would have believed the mechanism
+was there.
+
+The reader now walks the discipline the docblock claims — start from the
+expression this program replaced, `appDefaultPermissionSetName(config.permissions)`,
+and consult `packages[]` only where it came back `undefined`.
+
+- **The condition is the resolved NAME, never the `permissions` container.**
+  Branching on the container re-creates the silent loss the reader program
+  exists to remove, one shape further along: a flattened level that carries
+  permission sets but marks none of them `isDefault` is legal today and
+  hand-authorable in any `objectstack.config.ts`, and a container-shaped
+  condition (`Array.isArray(flattened)`, with or without `&& length > 0`) shorts
+  it past the whole `packages[]` pass and answers `undefined` — nothing thrown,
+  nothing logged, every member of the app back down to the platform floor alone.
+  Reading the answer also retires the `[]`-is-truthy trap rather than patching
+  around it.
+- **The package order is resolved BEFORE the top level is consulted.**
+  `resolveArtifactPackageOrder` refuses a malformed `packages` — not an array,
+  an entry inlined instead of wrapped under `manifest:`, a duplicate package id
+  — with an ADR-0112 envelope this reader does not catch, and that refusal must
+  not become conditional on whether the flattened level happened to name a
+  default first. An artifact is either loadable or refused; which level answered
+  is not part of that question.
+- **No emitted artifact changes its answer.** Measured, not argued: 26 shapes —
+  the composed additive artifact, its option-B derivative, the collection-zoo
+  fixtures behind the #15004 acceptance pin, every config the unit suite drives,
+  the three malformed-`packages` refusals, and the hand-authored mixed shapes —
+  return byte-identical results before and after, with `@objectstack/plugin-security`
+  rebuilt and the change proven present in `dist/` on each leg.