feat(web): continue source-backed implementation waves

web/protocol/compositor-commands.ts

@@ -0,0 +1,8 @@
+import type { CompositorGraphIR } from "./compositor";
+
+/** Workbench command payload for the bounded local compositor evaluator. */
+export const compositorCommands = Object.freeze({
+  evaluate(graph: CompositorGraphIR): CompositorGraphIR {
+    return structuredClone(graph);
+  },
+  } as const);