feat: add managed skills gating

skills/sag/SKILL.md

@@ -0,0 +1,15 @@
+---
+name: sag
+description: ElevenLabs text-to-speech with mac-style say UX.
+metadata: {"clawdis":{"requires":{"bins":["sag"]}}}
+---
+
+# sag
+
+Use `sag` to speak or stream text to speakers. Start with:
+
+```bash
+sag --help
+```
+
+Confirm the voice/speaker before long output.