SubagentRun.id previously promised uniqueness only within one parent,
but the unified manager indexes every external activation by that id in
one runtime-wide resident map. Publication also checks the live Agent and
Session registries. Two compliant-looking provider results could therefore
collide even when they belonged to different parents.
Document the existing shared Session id namespace across all parents,
providers, and local Sessions. Update the package reference, bilingual
type-equivalent declaration, and the current upgrade guide so custom
providers know to replace parent-local counters with fresh execution ids.
The shipped ACP, DSH SDK, Codex, and Claude Code providers already mint
UUIDs; no runtime mapping or additional retained identity state is needed.
Add a cross-parent collision test through startActivation. It proves that
publication rejects the duplicate, disposes only the new external handle,
leaves the second parent catalog empty, and preserves the first catalog
entry and execution result through normal cleanup.
Validation: all seven external-lifecycle tests pass, as do scoped bilingual
pairing, verify-upgrade-guides, doc-sync, and full lint. Cordis catalog and
inspection-catalog regeneration produces no tracked artifact changes.