feat(audit): M5.3 response-capture increments — request headers, ceiling-hits counter, per-method body opt-out (T7)

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.

src/ZB.MOM.WW.ScadaBridge.AuditLog/Configuration/PerTargetRedactionOverride.cs

@@ -25,4 +25,15 @@ public sealed class PerTargetRedactionOverride
     /// rows.
     /// </summary>
     public string? RedactSqlParamsMatching { get; set; }
+
+    /// <summary>
+    /// When <c>true</c>, the inbound API audit row for this target records
+    /// request/response headers and metadata (status, duration, actor, etc.)
+    /// but the request and response body strings are omitted
+    /// (<c>RequestSummary</c> / <c>ResponseSummary</c> are left null). The
+    /// audit row itself is always emitted — only the body content is suppressed.
+    /// Null (the default, equivalent to <c>false</c>) means body capture
+    /// proceeds normally up to <see cref="AuditLogOptions.InboundMaxBytes"/>.
+    /// </summary>
+    public bool SkipBodyCapture { get; set; }
 }