Copilot agent-mode fixes for PR 31

Author: data-douser

.github/instructions/csharp.instructions.md

@@ -1,3 +1,7 @@
+---
+applyTo: "src/**/*.cs"
+description: "C# coding patterns, architecture conventions, and project-specific guidance for CodeQL Development Toolkit"
+---
 # C# Code Instructions for CodeQL Development Toolkit
 
 ## Code Style and Conventions

.github/instructions/liquid.instructions.md

@@ -1,3 +1,7 @@
+---
+applyTo: "src/**/Templates/**/*.liquid"
+description: "Liquid template structure and conventions for CodeQL file generation"
+---
 # Liquid Template Instructions for CodeQL Development Toolkit
 
 ## Template Purpose and Structure

.github/instructions/repository.instructions.md

@@ -1,3 +1,7 @@
+---
+applyTo: "**/*"
+description: "High-level project context, repository structure, and development workflow guidance"
+---
 # CodeQL Development Toolkit Repository Instructions
 
 ## Project Overview

.github/workflows/copilot-setup-steps.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Setup .NET 6.0.x
       uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: 6.0.x
+        dotnet-version: 6.0.0
 
     - name: Verify .NET installation
       run: |