fix(subagent): pin delegated child approvals to 'never' within the inherited sandbox scope

A delegated in-process child now acts only within the sandbox scope fixed
at delegation: captureDelegatedPolicyOverrides still snapshots the parent's
explicit sandbox override but pins the child approval policy to 'never'
(instead of inheriting the parent's), so every child ask — sandbox_permissions
escalations included — is rejected deterministically by ApprovalService
before any answerer, with the audit pair still logged. Every in-process
child additionally receives the scoped subagent:delegation runtime-context
statement telling it to report a scope limitation instead of retrying.

Supersedes the approval half of the policy-inheritance decision (new Agent
Note cross-linked from both prior notes and the approval-seam Q&A); refreshed
child snapshot fixtures carry the pinned event, and
subagent-published-run-failure now persists a one-event child log.

packages/subagent/tool-subagent-report/tests/tool-subagent-report.spec.ts

@@ -411,9 +411,9 @@ describe('dsh-tool-subagent-report', () => {
   })
 })
 
-/** Prove report delivery uses ordinary logged user messages. */
+/** Prove report delivery uses ordinary logged user messages (framework runtime-context snapshots excluded). */
 function userTexts(events: readonly SessionEvent[]): string[] {
-  return events.flatMap(event => event.type === 'user/message'
+  return events.flatMap(event => event.type === 'user/message' && event.data.source.kind !== 'plugin'
     ? event.data.content.flatMap(block => block.type === 'text' ? [block.text] : [])
     : [])
 }