Implement MongoDB-based storage for Pack Run approval, artifact, log, and state management

- Added MongoPackRunApprovalStore for managing approval states with MongoDB.
- Introduced MongoPackRunArtifactUploader for uploading and storing artifacts.
- Created MongoPackRunLogStore to handle logging of pack run events.
- Developed MongoPackRunStateStore for persisting and retrieving pack run states.
- Implemented unit tests for MongoDB stores to ensure correct functionality.
- Added MongoTaskRunnerTestContext for setting up MongoDB test environment.
- Enhanced PackRunStateFactory to correctly initialize state with gate reasons.

src/Aoc/__Libraries/StellaOps.Aoc/AocGuardOptions.cs

@@ -1,29 +1,49 @@
-using System.Collections.Immutable;
+using System.Collections.Immutable;
+using System.Linq;
 
 namespace StellaOps.Aoc;
 
-public sealed record AocGuardOptions
-{
-    private static readonly ImmutableHashSet<string> DefaultRequiredTopLevel = new[]
-    {
-        "tenant",
-        "source",
-        "upstream",
-        "content",
-        "linkset",
-    }.ToImmutableHashSet(StringComparer.OrdinalIgnoreCase);
-
-    public static AocGuardOptions Default { get; } = new();
-
-    public ImmutableHashSet<string> RequiredTopLevelFields { get; init; } = DefaultRequiredTopLevel;
-
-    /// <summary>
-    /// When true, signature metadata is required under upstream.signature.
-    /// </summary>
-    public bool RequireSignatureMetadata { get; init; } = true;
-
-    /// <summary>
-    /// When true, tenant must be a non-empty string.
-    /// </summary>
-    public bool RequireTenant { get; init; } = true;
-}
+public sealed record AocGuardOptions
+{
+    private static readonly ImmutableHashSet<string> DefaultRequiredTopLevel = new[]
+    {
+        "tenant",
+        "source",
+        "upstream",
+        "content",
+        "linkset",
+    }.ToImmutableHashSet(StringComparer.OrdinalIgnoreCase);
+
+    private static readonly ImmutableHashSet<string> DefaultAllowedTopLevel = DefaultRequiredTopLevel
+        .Union(new[]
+        {
+            "_id",
+            "identifiers",
+            "attributes",
+            "supersedes",
+            "createdAt",
+            "created_at",
+            "ingestedAt",
+            "ingested_at"
+        }, StringComparer.OrdinalIgnoreCase)
+        .ToImmutableHashSet(StringComparer.OrdinalIgnoreCase);
+
+    public static AocGuardOptions Default { get; } = new();
+
+    public ImmutableHashSet<string> RequiredTopLevelFields { get; init; } = DefaultRequiredTopLevel;
+
+    /// <summary>
+    /// Optional allowlist for top-level fields. Unknown fields trigger ERR_AOC_007.
+    /// </summary>
+    public ImmutableHashSet<string> AllowedTopLevelFields { get; init; } = DefaultAllowedTopLevel;
+
+    /// <summary>
+    /// When true, signature metadata is required under upstream.signature.
+    /// </summary>
+    public bool RequireSignatureMetadata { get; init; } = true;
+
+    /// <summary>
+    /// When true, tenant must be a non-empty string.
+    /// </summary>
+    public bool RequireTenant { get; init; } = true;
+}