1. Request headers in Extra JSON (AuditWriteMiddleware): adds a `requestHeaders`
object to the existing Extra JSON alongside remoteIp/userAgent; headers whose
names appear in AuditLogOptions.HeaderRedactList (Authorization, X-Api-Key,
Cookie, Set-Cookie by default) are replaced with "<redacted>" using
OrdinalIgnoreCase matching — same policy as ScadaBridgeAuditRedactor.
2. AuditInboundCeilingHits counter: new IAuditInboundCeilingHitsCounter interface
+ NoOpAuditInboundCeilingHitsCounter default; AuditCentralHealthSnapshot
implements the interface (Interlocked field, thread-safe) and exposes
AuditInboundCeilingHits on IAuditCentralHealthSnapshot; AddAuditLog registers
the NoOp default, AddAuditLogCentralMaintenance forwards to the snapshot;
AuditWriteMiddleware accepts the counter as an optional ctor arg and increments
it once per request where either the request or response body hit the cap.
3. Per-method SkipBodyCapture opt-out: adds SkipBodyCapture bool to
PerTargetRedactionOverride; AuditWriteMiddleware consults the per-target
override map at the start of InvokeAsync (before EnableBuffering) and, when
set, skips body read + capture entirely — the audit row still emits with
headers/metadata but null RequestSummary/ResponseSummary; truncation flags
are also cleared so the ceiling-hits counter is not bumped for opted-out methods.