Removing one skill's hooks no longer removes another skill's

A hook is an action set up to run automatically at certain points while Claude Code works. A skill is a packaged set of instructions Claude Code can load, and a skill can add hooks for the length of a session (a single working conversation).

When session hooks are removed, the removal can now be limited to hooks that came from one particular skill's folder. Before, it removed matching hooks everywhere. Clearing all session hooks now also clears one more piece of stored state.