fix: isolate actor inspection context

[cevr]

Summary

• separate the actor-owned inspection dispatcher from ambient InspectorService
• prevent nested actors from recursively inheriting parent and system sinks
• route task inspection through actor-local, system, and cluster inspectors
• add a patch changeset

Checks

• bun run gate
• 325 package tests
• core, React, and Solid example gates

Counsel

One deep Counsel review agreed with the defect and rejected a marker-based workaround. It recommended this internal context split. No public API changes.