feat(auditlog): SiteAuditTelemetryActor + ISiteStreamAuditClient seam (#23)

src/ScadaLink.AuditLog/Site/Telemetry/SiteAuditTelemetryOptions.cs

@@ -0,0 +1,28 @@
+namespace ScadaLink.AuditLog.Site.Telemetry;
+
+/// <summary>
+/// Tuning knobs for the site-side <see cref="SiteAuditTelemetryActor"/> drain
+/// loop. Defaults mirror Bundle D's plan: drain every 5 s while rows are
+/// flowing (busy), every 30 s when the queue is empty (idle).
+/// </summary>
+public sealed class SiteAuditTelemetryOptions
+{
+    /// <summary>
+    /// Maximum number of <see cref="ScadaLink.Commons.Entities.Audit.AuditEvent"/>
+    /// rows read from the site SQLite queue and pushed in a single gRPC batch.
+    /// </summary>
+    public int BatchSize { get; set; } = 256;
+
+    /// <summary>
+    /// Delay between drains when the previous drain found at least one Pending
+    /// row OR the previous push faulted. Re-drain quickly to keep telemetry
+    /// flowing and to retry transient gRPC errors.
+    /// </summary>
+    public int BusyIntervalSeconds { get; set; } = 5;
+
+    /// <summary>
+    /// Delay between drains when the previous drain found no Pending rows.
+    /// Longer interval avoids hammering an idle SQLite + gRPC channel.
+    /// </summary>
+    public int IdleIntervalSeconds { get; set; } = 30;
+}