chore(changeset): patch @objectstack/skills for the objectstack-automation identity-assignment paragraph

skills/** ships in @objectstack/skills (sync-catalog copies it into the
package's dist), so the teaching change publishes and carries a patch
changeset with both declaration lines.

Claude-Session: https://claude.ai/code/session_01JQwxba5RipjC9aRL8Cjjux
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

.changeset/26502-automation-skill-identity-assignment-refusal.md

@@ -0,0 +1,12 @@
+---
+'@objectstack/skills': patch
+---
+
+docs(skills): objectstack-automation says a `runAs: 'system'` flow is refused identity-assignment writes, and names the remedy
+
+Clause-②: no
+Metadata-protocol: none
+
+- **Before.** The `runAs: 'system'` guidance called system context the trusted-writer channel and never said that a system flow's insert, update, delete, transfer, restore or purge of `sys_user_position`, `sys_user_permission_set`, `sys_invitation` or `sys_member` is refused with `PERMISSION_DENIED`. An agent following the skill wrote a system flow to grant a permission set and met the refusal at run time.
+- **Now.** A paragraph beside "Elevate the write, not the flow" states the refusal, says a dedicated system subflow does not lift it, and gives the remedy the refusal prescribes: grant positions and permission sets from a flow whose `runAs` is `'user'`, judged by the delegated-administration gate as the user it acts for; change invitations and memberships through the organization endpoints. Eval 11 in `evals/flows-triggers-approvals.json` checks that an answer routes such a grant through a `runAs: 'user'` flow.
+- No schema, key or behaviour changes.