Add llamanager plugin (#171)

* feat: add Llamanager plugin

* fix image paths in README

* docs: fix validation issues

* fix: handle missing trailing separator in modelfile directory

* fix: escape user input in shell commands

* fix: disable modelfile editor when path is unset or misconfigured

* fix: handle invalid Modelfile directory

* docs: update README

* fix: reload launcher model from config

* docs: update demo assets

llamanager/widget.luau

@@ -0,0 +1,6 @@
+function onClick()
+    noctalia.togglePanel("marccvictoria/llamanager:panel")
+end
+
+-- main
+barWidget.setGlyph("topology-star-3")