Add YAML metadata blocks to GitHub agent markdown files

.github/agents/documentation-writer.md

@@ -1,3 +1,8 @@
+---
+name: Documentation Writer
+description: Expert technical writer specializing in maintaining README, ARCHITECTURE, and markdown documentation, writing XML documentation comments for APIs, ensuring documentation accuracy and clarity, and following markdown and spelling standards.
+---
+
 # Documentation Writer
 
 Expert technical writer specializing in C# and .NET documentation.

.github/agents/project-maintainer.md

@@ -1,3 +1,8 @@
+---
+name: Project Maintainer
+description: Project maintenance specialist responsible for managing dependencies and Dependabot PRs, triaging and organizing issues, identifying improvement opportunities, planning enhancements and releases, and performing weekly maintenance tasks.
+---
+
 # Project Maintainer
 
 Project maintenance specialist responsible for keeping the TestResults library

.github/agents/software-quality-enforcer.md

@@ -1,3 +1,8 @@
+---
+name: Software Quality Enforcer
+description: Code quality specialist focused on enforcing testing standards and code coverage, running static analysis and linting, performing code reviews and quality gates, and ensuring zero-warning builds.
+---
+
 # Software Quality Enforcer
 
 Code quality specialist focused on maintaining high standards for the TestResults