docs+code: close Theme 1 — 24 design-doc / XML-doc drift findings

Doc/XML-comment drift + small adherence fixes across 17 modules. Highlights:
- Host-017: site CoordinatedShutdown ordering — SiteStreamGrpcServer gains
  CancelAllStreams() (refuse new streams, cancel active), wired into
  Program.cs site branch via ApplicationStopping.
- InboundAPI-021: ParentExecutionId now travels on RouteToGet/SetAttributes
  symmetric with RouteToCallRequest; RouteHelper stamps from _parentExecutionId.
- ClusterInfra-012: ClusterOptionsValidator now requires both seed nodes.
- Comm-018: SiteCommunicationActor.HeartbeatMessage.IsActive derived from
  cluster leader check (was hardcoded true).
- DM-020: reconciliation audit row attributes the current user, not prior deployer.
- SEL-019: EventLogPurgeService early-exits on standby via active-node check.
- Plus comment/XML-doc accuracy fixes across AuditLog, ConfigurationDatabase,
  NotificationOutbox, SiteRuntime, SiteCallAudit; doc refreshes for Component-
  Commons / -ManagementService / -CLI / -ExternalSystemGateway / -HealthMonitoring
  / -Transport / -ConfigurationDatabase; CD-023 index-name doc alignment.

11 new regression tests (RouteHelper x4, SiteStreamGrpcServer x2,
ClusterOptionsValidator x1, SiteCommunicationActor x1, DeploymentService x1,
EventLogPurgeService x3). Build clean (0 warnings); InboundAPI/Communication/
Host suites all green. README regenerated: 112 open (was 136).

code-reviews/SiteRuntime/findings.md

@@ -1307,7 +1307,7 @@ failure response).
 |--|--|
 | Severity | Low |
 | Category | Documentation & comments |
-| Status | Open |
+| Status | Resolved |
 | Location | `src/ScadaLink.SiteRuntime/Messages/ReplicationMessages.cs:10`, `src/ScadaLink.SiteRuntime/Messages/ReplicationMessages.cs:13`, `src/ScadaLink.SiteRuntime/Messages/ReplicationMessages.cs:15`, `src/ScadaLink.SiteRuntime/Messages/ReplicationMessages.cs:17`, `src/ScadaLink.SiteRuntime/Messages/ReplicationMessages.cs:19`, `src/ScadaLink.SiteRuntime/Messages/ReplicationMessages.cs:25`, `src/ScadaLink.SiteRuntime/Messages/ReplicationMessages.cs:28`, `src/ScadaLink.SiteRuntime/Messages/ReplicationMessages.cs:30`, `src/ScadaLink.SiteRuntime/Messages/ReplicationMessages.cs:32`, `src/ScadaLink.SiteRuntime/Messages/ReplicationMessages.cs:34` |
 
 **Description**
@@ -1334,3 +1334,13 @@ inbound vs outbound split with a marker base type (currently they're just
 named conventionally) so `Receive<ReplicateXxx>` vs `Receive<ApplyXxx>` is
 expressed at the type level — but that's optional and out of scope for a
 docs-only finding.
+
+**Resolution (2026-05-28):**
+
+Added a one-line `<summary>` to each of the ten records
+(`ReplicateConfigDeploy`/`Remove`/`SetEnabled`/`Artifacts`/`StoreAndForward` and
+`ApplyConfigDeploy`/`Remove`/`SetEnabled`/`Artifacts`/`StoreAndForward`) naming
+the direction (outbound to peer / inbound from peer) and what is replicated.
+The two pre-existing group-header XML blocks were converted to plain `//`
+comments to avoid orphaned doc-summaries above the first record in each group.
+Marker-base-type idea left out of scope.