Implement main-thread Camino sessions and synchronous CRDT editing

src/bindings/react.ts

@@ -15,6 +15,8 @@ export function generateReactBindings(
   const declarations: string[] = [];
   const type = (value: ValueType): string => {
     switch (value.kind) {
+      case "variant":
+        throw new Error("Variants require the Camino portable value runtime; legacy RPC bindings are unsupported");
       case "builtin":
         if (value.name !== "unit") throw new Error(`Unsupported React props builtin ${value.name}`);
         return "null";
@@ -85,6 +87,7 @@ export function generateReactBindings(
   const browserValue = (value: ValueType, seen: Set<string>): boolean => {
     if (value.kind === "message") return false;
     if (value.kind === "builtin") return value.name === "unit";
+    if (value.kind === "variant") return false;
     if (value.kind === "record") return Object.values(value.fields).every((field) => browserValue(field, seen));
     if (value.kind === "list" || value.kind === "optional") return browserValue(value.value, seen);
     if (value.kind === "object-ref" && value.expectation.kind === "interface") {