feat: add managed skills gating

skills/mcporter/SKILL.md

@@ -0,0 +1,15 @@
+---
+name: mcporter
+description: Manage MCP servers (install, list, sync) with mcporter.
+metadata: {"clawdis":{"requires":{"bins":["mcporter"]}}}
+---
+
+# mcporter
+
+Use the `mcporter` CLI to install, list, and sync MCP servers. Start with:
+
+```bash
+mcporter --help
+```
+
+If the tool is missing, ask the user to install it from the Tools tab.