Synchronize delivery test fixtures and record the concurrency audit

docs/roadmap/race.md

@@ -1,6 +1,9 @@
 # Roadmap: synchronize delivery test fixtures
 
-Status: planned; implementation has not started.
+Status: complete; fixture synchronization and race-enabled verification passed.
+
+The [concurrency audit](audit.md) records the wider review, additional findings,
+corrections, and final verification evidence.
 
 ## Objective and evidence
 
@@ -101,3 +104,10 @@ This verification addresses the reported defect. Future release validation
 continues to follow the [release procedure](../release.md). The correction is
 suitable for a subsequent patch release; preparation and publication are separate
 work under that procedure, preserving the published v0.4.0 contents.
+
+**Completed:** Both delivery fixtures and all their consumers use mutex-protected
+updates and independent snapshots. Existing mismatch, note, asset, retry, and
+source-preservation assertions remain in place. Focused workflow checks and the
+full offline race-enabled suite passed with Go 1.26.8; the compiled API/dependency
+check passed. The audit also corrected public delivery fixture ownership,
+Gitea scalar observations, HTTP assertion handling, and server cleanup.