Merge remote-tracking branch 'origin/master' into codex/pr335-merge-master-20260719

docs/rfc/INDEX.md

@@ -22,7 +22,6 @@ Generated by `pnpm run gen-rfc-index` from the RFC tree — never edit by hand;
 |---|---|
 | [Prune dead public and result surface](proposed/simplification/2026-07-04-prune-dead-core-spine-surface.md) | 2026-07-04 |
 | [Make JSON-RPC completion and transport directional](proposed/simplification/2026-07-19-make-jsonrpc-directional.md) | 2026-07-19 |
-| [Retire the standalone subagent mock package](proposed/simplification/2026-07-19-retire-subagent-mock-package.md) | 2026-07-19 |
 
 ### Architecture
 
@@ -122,6 +121,7 @@ Generated by `pnpm run gen-rfc-index` from the RFC tree — never edit by hand;
 | [Drop unconsumed skill provider events](implemented/simplification/2026-07-12-drop-unconsumed-skill-provider-events.md) | 2026-07-12 |
 | [Prune unused web seam fields](implemented/simplification/2026-07-12-prune-unused-web-seam-fields.md) | 2026-07-12 |
 | [Simplify session-log representation](implemented/simplification/2026-07-12-simplify-session-log-representation.md) | 2026-07-12 |
+| [Retire the standalone subagent mock package](implemented/simplification/2026-07-19-retire-subagent-mock-package.md) | 2026-07-19 |
 | [Use one surface manager per session](implemented/simplification/2026-07-19-use-one-session-surface-manager.md) | 2026-07-19 |
 
 ### Architecture