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/TaskRunner/StellaOps.TaskRunner/StellaOps.TaskRunner.Client/StellaOps.TaskRunner.Client.csproj

@@ -4,6 +4,7 @@
     <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <LangVersion>preview</LangVersion>
     <Description>SDK client for StellaOps TaskRunner WebService API</Description>
   </PropertyGroup>

src/TaskRunner/StellaOps.TaskRunner/StellaOps.TaskRunner.Core/StellaOps.TaskRunner.Core.csproj

@@ -10,7 +10,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <LangVersion>preview</LangVersion>
-    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
   
 

src/TaskRunner/StellaOps.TaskRunner/StellaOps.TaskRunner.Infrastructure/StellaOps.TaskRunner.Infrastructure.csproj

@@ -11,6 +11,6 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <LangVersion>preview</LangVersion>
-    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 </Project>

src/TaskRunner/StellaOps.TaskRunner/StellaOps.TaskRunner.WebService/StellaOps.TaskRunner.WebService.csproj

@@ -10,7 +10,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <LangVersion>preview</LangVersion>
-    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
   
 

src/TaskRunner/StellaOps.TaskRunner/StellaOps.TaskRunner.Worker/StellaOps.TaskRunner.Worker.csproj

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

src/TaskRunner/__Libraries/StellaOps.TaskRunner.Persistence/StellaOps.TaskRunner.Persistence.csproj

@@ -6,7 +6,7 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <LangVersion>preview</LangVersion>
-    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <RootNamespace>StellaOps.TaskRunner.Persistence</RootNamespace>
     <AssemblyName>StellaOps.TaskRunner.Persistence</AssemblyName>
     <Description>Consolidated persistence layer for StellaOps TaskRunner module (EF Core + Raw SQL)</Description>