Implement main-thread Camino sessions and synchronous CRDT editing

src/bindings/index.ts

@@ -112,6 +112,8 @@ export const generateTypeScriptBindings = (
   const messages = new Map<string, 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":
         return value.name === "unit" ? "null" : "QxWatchHandle";
       case "scalar":
@@ -340,6 +342,7 @@ export const generateTypeScriptBindings = (
   // A used port still fails above if its own required codec is missing.
   const hasCodec = (value: ValueType): boolean => {
     if (value.kind === "message") return !!options.messages?.[value.descriptorId];
+    if (value.kind === "variant") return false;
     if (value.kind === "record") return Object.values(value.fields).every(hasCodec);
     if (value.kind === "list" || value.kind === "optional") return hasCodec(value.value);
     return true;