feat(10.1-02): run registered toolbar actions and scope plugin CSS per controller

- ListToolbar renders server-filtered actions after delete as outline buttons, busy during their POST
- ListView posts {} to toolbar/{action}, toasts, reloads the list and refetches the header partial
- Lists load controller assets too, so other controllers' stylesheet links are disabled on every open
- Vite dev server proxies {prefix}/assets to summer serve; dist rebuilt

admin/tests/fixtures/extension.list-schema.json

@@ -11,9 +11,15 @@
     "recordUrl": "acme/demo/widgets/update/:id",
     "toolbarButtons": [
       "create",
-      "delete"
+      "delete",
+      "recount"
+    ],
+    "toolbarActions": [
+      {
+        "name": "recount",
+        "label": "Recount"
+      }
     ],
-    "toolbarActions": [],
     "assets": {
       "scripts": [],
       "styles": [