feat(auditlog): ParentExecutionId column on AuditEvent + central AuditLog

src/ScadaLink.ConfigurationDatabase/Migrations/20260521210254_AddAuditLogParentExecutionId.cs

@@ -0,0 +1,59 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ScadaLink.ConfigurationDatabase.Migrations
+{
+    /// <summary>
+    /// Adds the <c>ParentExecutionId</c> correlation column to the centralized
+    /// <c>AuditLog</c> table (#23). <c>ParentExecutionId</c> carries the
+    /// <c>ExecutionId</c> of the execution that spawned this run, letting a
+    /// spawned execution point back at its spawner — a sibling to the universal
+    /// per-run <c>ExecutionId</c>.
+    ///
+    /// The change is purely additive:
+    /// 1. <c>ParentExecutionId uniqueidentifier NULL</c> is added with no default,
+    ///    so the operation is a metadata-only <c>ALTER TABLE … ADD</c> — it does
+    ///    NOT rewrite the monthly-partitioned <c>AuditLog</c> table, and
+    ///    historical rows stay <c>NULL</c> (no backfill).
+    /// 2. <c>IX_AuditLog_ParentExecution</c> is created via raw SQL so it lands on
+    ///    the <c>ps_AuditLog_Month(OccurredAtUtc)</c> partition scheme, matching
+    ///    every other <c>IX_AuditLog_*</c> index. Keeping it partition-aligned
+    ///    preserves the partition-switch purge path (see
+    ///    AuditLogRepository.SwitchOutPartitionAsync).
+    /// </summary>
+    public partial class AddAuditLogParentExecutionId : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<Guid>(
+                name: "ParentExecutionId",
+                table: "AuditLog",
+                type: "uniqueidentifier",
+                nullable: true);
+
+            // Raw SQL so the index is created on the partition scheme — EF's
+            // CreateIndex cannot express the ON ps_AuditLog_Month(OccurredAtUtc)
+            // clause. Mirrors IX_AuditLog_Execution (filtered, aligned).
+            migrationBuilder.Sql(@"
+CREATE NONCLUSTERED INDEX IX_AuditLog_ParentExecution
+ON dbo.AuditLog (ParentExecutionId)
+WHERE ParentExecutionId IS NOT NULL
+ON ps_AuditLog_Month(OccurredAtUtc);");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.Sql(@"
+IF EXISTS (SELECT 1 FROM sys.indexes WHERE name = 'IX_AuditLog_ParentExecution' AND object_id = OBJECT_ID('dbo.AuditLog'))
+    DROP INDEX IX_AuditLog_ParentExecution ON dbo.AuditLog;");
+
+            migrationBuilder.DropColumn(
+                name: "ParentExecutionId",
+                table: "AuditLog");
+        }
+    }
+}

src/ScadaLink.ConfigurationDatabase/Migrations/ScadaLinkDbContextModelSnapshot.cs

@@ -96,6 +96,9 @@ namespace ScadaLink.ConfigurationDatabase.Migrations
                         .IsUnicode(false)
                         .HasColumnType("varchar(32)");
 
+                    b.Property<Guid?>("ParentExecutionId")
+                        .HasColumnType("uniqueidentifier");
+
                     b.Property<bool>("PayloadTruncated")
                         .HasColumnType("bit");
 
@@ -149,6 +152,10 @@ namespace ScadaLink.ConfigurationDatabase.Migrations
                         .IsDescending()
                         .HasDatabaseName("IX_AuditLog_OccurredAtUtc");
 
+                    b.HasIndex("ParentExecutionId")
+                        .HasDatabaseName("IX_AuditLog_ParentExecution")
+                        .HasFilter("[ParentExecutionId] IS NOT NULL");
+
                     b.HasIndex("SourceSiteId", "OccurredAtUtc")
                         .IsDescending(false, true)
                         .HasDatabaseName("IX_AuditLog_Site_Occurred");