feat(audit): Apply TreatWarningsAsErrors=true to 160+ production csproj files

Sprint: SPRINT_20251229_049_BE_csproj_audit_maint_tests
Tasks: AUDIT-0001 through AUDIT-0147 APPLY tasks (approved decisions 1-9)

Changes:
- Set TreatWarningsAsErrors=true for all production .NET projects
- Fixed nullable warnings in Scanner.EntryTrace, Scanner.Evidence,
  Scheduler.Worker, Concelier connectors, and other modules
- Injected TimeProvider/IGuidProvider for deterministic time/ID generation
- Added path traversal validation in AirGap.Bundle
- Fixed NULL handling in various cursor classes
- Third-party GostCryptography retains TreatWarningsAsErrors=false (preserves original)
- Test projects excluded per user decision (rejected decision 10)

Note: All 17 ACSC connector tests pass after snapshot fixture sync

src/ExportCenter/StellaOps.ExportCenter.RiskBundles/StellaOps.ExportCenter.RiskBundles.csproj

@@ -4,7 +4,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <LangVersion>preview</LangVersion>
-    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="../StellaOps.ExportCenter/StellaOps.ExportCenter.Infrastructure/StellaOps.ExportCenter.Infrastructure.csproj" />

src/ExportCenter/StellaOps.ExportCenter/StellaOps.ExportCenter.Client/StellaOps.ExportCenter.Client.csproj

@@ -5,6 +5,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <LangVersion>preview</LangVersion>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <Description>SDK client for StellaOps ExportCenter WebService API</Description>
   </PropertyGroup>
 

src/ExportCenter/StellaOps.ExportCenter/StellaOps.ExportCenter.Core/StellaOps.ExportCenter.Core.csproj

@@ -8,7 +8,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <LangVersion>preview</LangVersion>
-    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <ItemGroup>

src/ExportCenter/StellaOps.ExportCenter/StellaOps.ExportCenter.Infrastructure/StellaOps.ExportCenter.Infrastructure.csproj

@@ -5,7 +5,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <LangVersion>preview</LangVersion>
-    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <ItemGroup>

src/ExportCenter/StellaOps.ExportCenter/StellaOps.ExportCenter.WebService/Distribution/Oci/OciRegistryConfig.cs

@@ -168,9 +168,9 @@ public sealed class RegistryTlsConfig
             return null;
 
         if (!string.IsNullOrEmpty(ClientKeyPassword))
-            return new X509Certificate2(ClientCertPath, ClientKeyPassword);
+            return X509CertificateLoader.LoadPkcs12FromFile(ClientCertPath, ClientKeyPassword);
 
-        return new X509Certificate2(ClientCertPath);
+        return X509CertificateLoader.LoadCertificateFromFile(ClientCertPath);
     }
 
     /// <summary>
@@ -217,7 +217,7 @@ public sealed class RegistryTlsConfig
     private X509Certificate2? LoadCaCertificate()
     {
         if (!string.IsNullOrEmpty(CaCertPath) && File.Exists(CaCertPath))
-            return new X509Certificate2(CaCertPath);
+            return X509CertificateLoader.LoadCertificateFromFile(CaCertPath);
 
         if (!string.IsNullOrEmpty(CaCertPem))
             return X509Certificate2.CreateFromPem(CaCertPem);

src/ExportCenter/StellaOps.ExportCenter/StellaOps.ExportCenter.WebService/ExceptionReport/ExceptionReportEndpoints.cs

@@ -20,8 +20,7 @@ public static class ExceptionReportEndpoints
     public static IEndpointRouteBuilder MapExceptionReportEndpoints(this IEndpointRouteBuilder app)
     {
         var group = app.MapGroup("/v1/exports/exceptions")
-            .WithTags("Exception Reports")
-            .WithOpenApi();
+            .WithTags("Exception Reports");
 
         group.MapPost("/", CreateReportAsync)
             .RequireAuthorization(StellaOpsResourceServerPolicies.ExportOperator)

src/ExportCenter/StellaOps.ExportCenter/StellaOps.ExportCenter.WebService/Lineage/LineageExportEndpoints.cs

@@ -24,8 +24,7 @@ public static class LineageExportEndpoints
     public static IEndpointRouteBuilder MapLineageExportEndpoints(this IEndpointRouteBuilder app)
     {
         var group = app.MapGroup("/api/v1/lineage")
-            .WithTags("Lineage Export")
-            .WithOpenApi();
+            .WithTags("Lineage Export");
 
         // POST /api/v1/lineage/export - Generate evidence pack
         group.MapPost("/export", ExportEvidencePackAsync)

src/ExportCenter/StellaOps.ExportCenter/StellaOps.ExportCenter.WebService/Program.cs

@@ -100,7 +100,7 @@ builder.Services.AddOpenApi();
 var routerOptions = builder.Configuration.GetSection("ExportCenter:Router").Get<StellaRouterOptionsBase>();
 builder.Services.TryAddStellaRouter(
     serviceName: "exportcenter",
-    version: typeof(Program).Assembly.GetName().Version?.ToString() ?? "1.0.0",
+    version: typeof(StellaOps.ExportCenter.WebService.Program).Assembly.GetName().Version?.ToString() ?? "1.0.0",
     routerOptions: routerOptions);
 
 var app = builder.Build();
@@ -168,3 +168,9 @@ app.MapDelete("/exports/{id}", (string id) => Results.NoContent())
 app.TryRefreshStellaRouterEndpoints(routerOptions);
 
 app.Run();
+
+// Make Program class accessible for integration testing
+namespace StellaOps.ExportCenter.WebService
+{
+    public partial class Program { }
+}

src/ExportCenter/StellaOps.ExportCenter/StellaOps.ExportCenter.WebService/SimulationExport/SimulationReportExporter.cs

@@ -283,11 +283,14 @@ public sealed class SimulationReportExporter : ISimulationReportExporter
                 Data = simulation.SignalAnalysis
             };
 
-            yield return new SimulationExportLine
+            if (simulation.OverrideAnalysis is not null)
             {
-                Type = "override_analysis",
-                Data = simulation.OverrideAnalysis
-            };
+                yield return new SimulationExportLine
+                {
+                    Type = "override_analysis",
+                    Data = simulation.OverrideAnalysis
+                };
+            }
         }
 
         // Emit distribution

src/ExportCenter/StellaOps.ExportCenter/StellaOps.ExportCenter.WebService/StellaOps.ExportCenter.WebService.csproj

@@ -6,7 +6,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <LangVersion>preview</LangVersion>
-    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.OpenApi" />

src/ExportCenter/StellaOps.ExportCenter/StellaOps.ExportCenter.Worker/StellaOps.ExportCenter.Worker.csproj

@@ -13,7 +13,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <LangVersion>preview</LangVersion>
-    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>