feat: move opkssh and warpgate into plugins (C3)

plugins/warpgate/locales/en.json

@@ -0,0 +1,10 @@
+{
+  "settings": {
+    "host": {
+      "useWarpgate": {
+        "label": "Warpgate Gateway",
+        "description": "This host connects through a Warpgate SSH proxy. Termix will handle the browser-based approval flow automatically after authenticating."
+      }
+    }
+  }
+}