Copilot / VS Code

Validates target-aware YAML frontmatter in .github/agents/**/*.md and legacy .github/chatmodes/**/*.chatmode.md: shared fields, real booleans, tools and model collections, subagents, handoffs, cloud MCP servers, metadata, and preview hooks. Embedded MCP and hooks also reach the shared security and policy rules. Enabled automatically wherever Copilot or VS Code repository content is detected.

Rule ID	Description	Default Severity	Autofix
copilot-agent-valid	Copilot and VS Code custom agents must use target-compatible frontmatter	error (auto)	-