Copilot installs agent files as gsd-*.agent.md (not gsd-*.md), so checkAgentsInstalled() always returned agents_installed=false for Copilot. - checkAgentsInstalled() now recognises both .md and .agent.md formats - getAgentsDir() respects GSD_AGENTS_DIR env override for testability Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>