What it does. Claude Code hook config with one SessionStart hook for the startup, clear, and compact events. It runs ${CLAUDE_PLUGIN_ROOT}/hooks/run-hook.cmd session-start through bash, with a PowerShell form of the same command, and waits for it to finish.
Why it’s here. This is what makes the skills trigger on their own in Claude Code: the hook puts the using-superpowers skill into the context at the start of each session and again after /clear or compaction. Claude Code loads hooks/hooks.json from a plugin automatically.