feat: synced blocks (transclusion) (#2163)

* feat: synced blocks (transclusion)

* fix:remove name

* make placeholders smaller

* feat: enforce strict transclusion schema

* fix: scope synced blocks to workspace, gate unsync on edit permission

* fix collab module error

apps/client/src/features/editor/components/transclusion/not-found-placeholder.tsx

@@ -0,0 +1,17 @@
+import { IconInfoCircle } from "@tabler/icons-react";
+import { useTranslation } from "react-i18next";
+import classes from "./transclusion.module.css";
+
+export default function NotFoundPlaceholder() {
+  const { t } = useTranslation();
+  return (
+    <div className={classes.placeholder}>
+      <IconInfoCircle
+        size={18}
+        stroke={1.6}
+        className={classes.placeholderIcon}
+      />
+      <span>{t("The original synced block no longer exists")}</span>
+    </div>
+  );
+}