Complete batch 012 (golden set diff) and 013 (advisory chat), fix build errors

Sprints completed:
- SPRINT_20260110_012_* (golden set diff layer - 10 sprints)
- SPRINT_20260110_013_* (advisory chat - 4 sprints)

Build fixes applied:
- Fix namespace conflicts with Microsoft.Extensions.Options.Options.Create
- Fix VexDecisionReachabilityIntegrationTests API drift (major rewrite)
- Fix VexSchemaValidationTests FluentAssertions method name
- Fix FixChainGateIntegrationTests ambiguous type references
- Fix AdvisoryAI test files required properties and namespace aliases
- Add stub types for CveMappingController (ICveSymbolMappingService)
- Fix VerdictBuilderService static context issue

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/BinaryIndex/__Libraries/StellaOps.BinaryIndex.GoldenSet/Models/GoldenSetDefinition.cs

@@ -0,0 +1,261 @@
+using System.Collections.Immutable;
+using System.Globalization;
+
+namespace StellaOps.BinaryIndex.GoldenSet;
+
+/// <summary>
+/// Represents ground-truth facts about a vulnerability's code-level manifestation.
+/// Hand-curated, reviewed like unit tests, tiny by design.
+/// </summary>
+public sealed record GoldenSetDefinition
+{
+    /// <summary>
+    /// Unique identifier (typically CVE ID, e.g., "CVE-2024-0727").
+    /// </summary>
+    public required string Id { get; init; }
+
+    /// <summary>
+    /// Affected component name (e.g., "openssl", "glibc").
+    /// </summary>
+    public required string Component { get; init; }
+
+    /// <summary>
+    /// Vulnerable code targets (functions, edges, sinks).
+    /// </summary>
+    public required ImmutableArray<VulnerableTarget> Targets { get; init; }
+
+    /// <summary>
+    /// Optional witness input for reproducing the vulnerability.
+    /// </summary>
+    public WitnessInput? Witness { get; init; }
+
+    /// <summary>
+    /// Metadata about the golden set.
+    /// </summary>
+    public required GoldenSetMetadata Metadata { get; init; }
+
+    /// <summary>
+    /// Content-addressed digest of the canonical form (computed, not user-provided).
+    /// </summary>
+    public string? ContentDigest { get; init; }
+}
+
+/// <summary>
+/// A specific vulnerable code target within a component.
+/// </summary>
+public sealed record VulnerableTarget
+{
+    /// <summary>
+    /// Function name (symbol or demangled name).
+    /// </summary>
+    public required string FunctionName { get; init; }
+
+    /// <summary>
+    /// Basic block edges that constitute the vulnerable path.
+    /// </summary>
+    public ImmutableArray<BasicBlockEdge> Edges { get; init; } = [];
+
+    /// <summary>
+    /// Sink functions that are reached (e.g., "memcpy", "strcpy").
+    /// </summary>
+    public ImmutableArray<string> Sinks { get; init; } = [];
+
+    /// <summary>
+    /// Constants/magic values that identify the vulnerable code.
+    /// </summary>
+    public ImmutableArray<string> Constants { get; init; } = [];
+
+    /// <summary>
+    /// Human-readable invariant that must hold for exploitation.
+    /// </summary>
+    public string? TaintInvariant { get; init; }
+
+    /// <summary>
+    /// Optional source file hint.
+    /// </summary>
+    public string? SourceFile { get; init; }
+
+    /// <summary>
+    /// Optional source line hint.
+    /// </summary>
+    public int? SourceLine { get; init; }
+}
+
+/// <summary>
+/// A basic block edge in the CFG.
+/// Format: "bbN->bbM" where N and M are block identifiers.
+/// </summary>
+public sealed record BasicBlockEdge
+{
+    /// <summary>
+    /// Source basic block identifier (e.g., "bb3").
+    /// </summary>
+    public required string From { get; init; }
+
+    /// <summary>
+    /// Target basic block identifier (e.g., "bb7").
+    /// </summary>
+    public required string To { get; init; }
+
+    /// <summary>
+    /// Parses an edge from string format "bbN->bbM".
+    /// </summary>
+    /// <param name="edge">The edge string to parse.</param>
+    /// <returns>A new BasicBlockEdge instance.</returns>
+    /// <exception cref="FormatException">Thrown when the edge format is invalid.</exception>
+    public static BasicBlockEdge Parse(string edge)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(edge);
+
+        var parts = edge.Split("->", StringSplitOptions.TrimEntries);
+        if (parts.Length != 2 || string.IsNullOrWhiteSpace(parts[0]) || string.IsNullOrWhiteSpace(parts[1]))
+        {
+            throw new FormatException(
+                string.Format(CultureInfo.InvariantCulture, "Invalid edge format: {0}. Expected 'bbN->bbM'.", edge));
+        }
+
+        return new BasicBlockEdge { From = parts[0], To = parts[1] };
+    }
+
+    /// <summary>
+    /// Tries to parse an edge from string format "bbN->bbM".
+    /// </summary>
+    /// <param name="edge">The edge string to parse.</param>
+    /// <param name="result">The parsed edge, or null if parsing failed.</param>
+    /// <returns>True if parsing succeeded; otherwise, false.</returns>
+    public static bool TryParse(string? edge, out BasicBlockEdge? result)
+    {
+        result = null;
+
+        if (string.IsNullOrWhiteSpace(edge))
+        {
+            return false;
+        }
+
+        var parts = edge.Split("->", StringSplitOptions.TrimEntries);
+        if (parts.Length != 2 || string.IsNullOrWhiteSpace(parts[0]) || string.IsNullOrWhiteSpace(parts[1]))
+        {
+            return false;
+        }
+
+        result = new BasicBlockEdge { From = parts[0], To = parts[1] };
+        return true;
+    }
+
+    /// <inheritdoc />
+    public override string ToString() => string.Concat(From, "->", To);
+}
+
+/// <summary>
+/// Witness input for reproducing the vulnerability.
+/// </summary>
+public sealed record WitnessInput
+{
+    /// <summary>
+    /// Command-line arguments to trigger the vulnerability.
+    /// </summary>
+    public ImmutableArray<string> Arguments { get; init; } = [];
+
+    /// <summary>
+    /// Human-readable invariant/precondition.
+    /// </summary>
+    public string? Invariant { get; init; }
+
+    /// <summary>
+    /// Reference to PoC file (content-addressed, format: "sha256:...").
+    /// </summary>
+    public string? PocFileRef { get; init; }
+}
+
+/// <summary>
+/// Metadata about the golden set.
+/// </summary>
+public sealed record GoldenSetMetadata
+{
+    /// <summary>
+    /// Author ID (who created the golden set).
+    /// </summary>
+    public required string AuthorId { get; init; }
+
+    /// <summary>
+    /// Creation timestamp (UTC).
+    /// </summary>
+    public required DateTimeOffset CreatedAt { get; init; }
+
+    /// <summary>
+    /// Source reference (advisory URL, commit hash, etc.).
+    /// </summary>
+    public required string SourceRef { get; init; }
+
+    /// <summary>
+    /// Reviewer ID (if reviewed).
+    /// </summary>
+    public string? ReviewedBy { get; init; }
+
+    /// <summary>
+    /// Review timestamp (UTC).
+    /// </summary>
+    public DateTimeOffset? ReviewedAt { get; init; }
+
+    /// <summary>
+    /// Classification tags (e.g., "memory-corruption", "heap-overflow").
+    /// </summary>
+    public ImmutableArray<string> Tags { get; init; } = [];
+
+    /// <summary>
+    /// Schema version for forward compatibility.
+    /// </summary>
+    public string SchemaVersion { get; init; } = GoldenSetConstants.CurrentSchemaVersion;
+}
+
+/// <summary>
+/// Status of a golden set in the corpus.
+/// </summary>
+public enum GoldenSetStatus
+{
+    /// <summary>Draft, not yet reviewed.</summary>
+    Draft,
+
+    /// <summary>Under review.</summary>
+    InReview,
+
+    /// <summary>Approved and active.</summary>
+    Approved,
+
+    /// <summary>Deprecated (CVE retracted or superseded).</summary>
+    Deprecated,
+
+    /// <summary>Archived (historical reference only).</summary>
+    Archived
+}
+
+/// <summary>
+/// Constants used throughout the Golden Set module.
+/// </summary>
+public static class GoldenSetConstants
+{
+    /// <summary>
+    /// Current schema version for golden set definitions.
+    /// </summary>
+    public const string CurrentSchemaVersion = "1.0.0";
+
+    /// <summary>
+    /// Regex pattern for CVE IDs.
+    /// </summary>
+    public const string CveIdPattern = @"^CVE-\d{4}-\d{4,}$";
+
+    /// <summary>
+    /// Regex pattern for GHSA IDs.
+    /// </summary>
+    public const string GhsaIdPattern = @"^GHSA-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{4}$";
+
+    /// <summary>
+    /// Regex pattern for basic block edge format.
+    /// </summary>
+    public const string EdgePattern = @"^bb\d+->bb\d+$";
+
+    /// <summary>
+    /// Regex pattern for content-addressed digest.
+    /// </summary>
+    public const string DigestPattern = @"^sha256:[a-f0-9]{64}$";
+}