refactor(comm): retire ClusterClient naming after the gRPC cutover

Phase 4 of the ClusterClient -> gRPC migration deleted the Akka transports
but left the naming behind: `ClusterClientSiteAuditClient` was transport-
agnostic and worked unchanged, so it survived the deletion under a name
that now describes a transport the repo no longer has. Same for a scatter
of doc-comments still framing gRPC as "the new transport" beside an Akka
one that is gone.

Renames it to `SiteCommunicationAuditClient` (and its test file) and
rewrites the stale comments to describe the single transport that exists.
Also tightens CLAUDE.md: drops the self-describing directory listing and
the 27-component enumeration in favour of the non-obvious parts only.

Behaviour-neutral: names and prose only. Recorded as the Phase 4
follow-up in docs/plans/2026-07-22-clusterclient-to-grpc-plan.md.

tests/ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests/Deployment/DebugViewTests.cs

@@ -28,7 +28,7 @@ namespace ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests.Deployment;
 /// <b>Tolerant terminal-state assertion (validation-behavior protocol):</b> whether
 /// <c>Connect</c> reaches a <b>Live</b> badge depends on the owning site returning a
 /// snapshot for the instance. Reading <c>DebugView.razor::Connect</c>: it awaits
-/// <c>DebugStreamService.StartStreamAsync</c> (a ClusterClient snapshot round-trip);
+/// <c>DebugStreamService.StartStreamAsync</c> (a site snapshot round-trip);
 /// on success it flips <c>_connected = true</c> (Live badge + success toast), and on
 /// any exception it surfaces a <c>Connect failed: …</c> error <c>.toast</c>. Either
 /// way <c>_connecting</c> resets, so the click always resolves — it never hangs. The