The skill meta-tools (listAvailableSkills, readSkillFile, listSkillFiles, load_skill, runSkillScript) queried the full skill catalog without checking the calling agent's bindings, so an agent scoped to a subset of skills could still read, load, or execute any skill via direct tool calls. Resolve the agent's bound skill ids from the tool context and filter/deny accordingly: a null binding set means no restriction (backward compatible), a non-null set (including empty) restricts access to that set — matching the system-prompt catalog filtering.
Closes#264
