v0.9.2 adds an activate_skill tool letting agents load skills autonomously

What this changes for operators

• Operators configuring skills now get a new agent-facing activate_skill tool: agents load full skill instructions on demand before matching work, shifting skill loading from operator-orchestrated to agent-initiated — a proactivity/authority change the operator should be aware of when scoping which skills are available.
• Workspace skills are reread on activation, so edits during an active session take effect (lazy loading preserved); verification is concrete (configure a skill, confirm the agent self-activates it and picks up an edit mid-session).