handoff: refresh date + offline test count after event-parser merge

Bring the doc header current with the merged event-row parser fix: bump
"Last updated" to 2026-06-23 and correct the Build And Test known-good
result from 321/321 to the actual 328/328 (build clean 0/0), noting the
+7 are the HistorianEventRowProtocolTests golden + gated-capture coverage.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC

docs/reverse-engineering/handoff.md

@@ -1,6 +1,6 @@
 # AVEVA Historian Managed Driver Handoff
 
-Last updated: 2026-06-22 (roadmap exhausted — no actionable pure-code tasks remain)
+Last updated: 2026-06-23 (event-row parser fix merged; roadmap still exhausted — no actionable pure-code tasks remain)
 
 > **Current status supersedes the historical blocker narrative below.** The
 > sections from "Active Blocker" onward are a preserved reverse-engineering
@@ -172,12 +172,14 @@ dotnet build .\Histsdk.slnx --no-restore
 dotnet test .\Histsdk.slnx --no-build --logger "console;verbosity=minimal"
 ```
 
-Current known-good result (2026-06-22):
+Current known-good result (2026-06-23):
 
 - Build succeeds (0 warnings / 0 errors).
-- Offline tests pass: 321/321 (live gRPC/integration tests skip cleanly without
+- Offline tests pass: 328/328 (live gRPC/integration tests skip cleanly without
   their env vars). Gated live tests add to this when `HISTORIAN_*` /
-  `HISTORIAN_GRPC_*` are set.
+  `HISTORIAN_GRPC_*` are set. The +7 over the prior 321 are the event-row parser
+  fix's golden + gated-capture coverage (`HistorianEventRowProtocolTests`:
+  markerless multi-row, the v11 gRPC header, and the 50-event stock-client capture).
 
 The workspace is a Git working tree (origin: gitea.dohertylan.com). Use
 normal git workflow for change tracking; the prior "no working tree, use