Restructure solution layout by module

src/Aoc/__Libraries/StellaOps.Aoc/AocGuardResult.cs

@@ -0,0 +1,14 @@
+using System.Collections.Immutable;
+
+namespace StellaOps.Aoc;
+
+public sealed record AocGuardResult(bool IsValid, ImmutableArray<AocViolation> Violations)
+{
+    public static AocGuardResult Success { get; } = new(true, ImmutableArray<AocViolation>.Empty);
+
+    public static AocGuardResult FromViolations(IEnumerable<AocViolation> violations)
+    {
+        var array = violations.ToImmutableArray();
+        return array.IsDefaultOrEmpty ? Success : new(false, array);
+    }
+}