add Hermes plugin for Ponytail with command support and documentation

after-install.md

@@ -0,0 +1,21 @@
+# Ponytail for Hermes installed
+
+Enable it if you did not install with `--enable`:
+
+```bash
+hermes plugins enable ponytail
+```
+
+Restart Hermes or the gateway after enabling.
+
+In shared gateways, restrict `/ponytail` to trusted users with Hermes slash-command access controls; runtime mode is process-local.
+
+Commands:
+
+- `/ponytail [lite|full|ultra|off]`
+- `/ponytail-review [target]`
+- `/ponytail-audit [target]`
+- `/ponytail-debt`
+- `/ponytail-help`
+
+Bundled skills are available as `ponytail:ponytail`, `ponytail:ponytail-review`, `ponytail:ponytail-audit`, `ponytail:ponytail-debt`, and `ponytail:ponytail-help`.