feat: Add new provenance and crypto registry documentation

- Introduced attestation inventory and subject-rekor mapping files for tracking Docker packages.
- Added a comprehensive crypto registry decision document outlining defaults and required follow-ups.
- Created an offline feeds manifest for bundling air-gap resources.
- Implemented a script to generate and update binary manifests for curated binaries.
- Added a verification script to ensure binary artefacts are located in approved directories.
- Defined new schemas for AdvisoryEvidenceBundle, OrchestratorEnvelope, ScannerReportReadyPayload, and ScannerScanCompletedPayload.
- Established project files for StellaOps.Orchestrator.Schemas and StellaOps.PolicyAuthoritySignals.Contracts.
- Updated vendor manifest to track pinned binaries for integrity.

src/__Libraries/StellaOps.PolicyAuthoritySignals.Contracts/Contracts.cs

@@ -0,0 +1,39 @@
+using System.Text.Json.Serialization;
+
+namespace StellaOps.PolicyAuthoritySignals.Contracts;
+
+public sealed record PolicyContract
+{
+    [JsonPropertyName("policyId")]
+    public string PolicyId { get; init; } = string.Empty;
+
+    [JsonPropertyName("version")]
+    public string Version { get; init; } = "0.1-draft";
+
+    [JsonPropertyName("rulesHash")]
+    public string? RulesHash { get; init; }
+}
+
+public sealed record TenantScope
+{
+    [JsonPropertyName("tenantId")]
+    public string TenantId { get; init; } = string.Empty;
+
+    [JsonPropertyName("scopes")]
+    public IReadOnlyList<string> Scopes { get; init; } = Array.Empty<string>();
+}
+
+public sealed record SignalSymbol
+{
+    [JsonPropertyName("symbolId")]
+    public string SymbolId { get; init; } = string.Empty;
+
+    [JsonPropertyName("language")]
+    public string? Language { get; init; }
+
+    [JsonPropertyName("package")]
+    public string? Package { get; init; }
+
+    [JsonPropertyName("version")]
+    public string? Version { get; init; }
+}

src/__Libraries/StellaOps.PolicyAuthoritySignals.Contracts/StellaOps.PolicyAuthoritySignals.Contracts.csproj

@@ -0,0 +1,7 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+</Project>