feat(simulation): expose semantic UI snapshots (#37802)

packages/tui/src/simulation/semantics.ts

@@ -0,0 +1,12 @@
+import type { Renderable } from "@opentui/core"
+import type { SimulationProtocol } from "@opencode-ai/simulation/protocol"
+
+type Definition = Omit<SimulationProtocol.Frontend.SemanticNode, "id" | "element" | "parent">
+
+const key = Symbol.for("opencode.simulation.semantics")
+
+const bind = (definition: () => Definition) => (renderable: Renderable) => {
+  Object.defineProperty(renderable, key, { value: definition, configurable: true })
+}
+
+export const SimulationSemantics = { bind }