feat(simulation): add driver controlled backend LLM (#35186)

packages/simulation/src/frontend/simulation.ts

@@ -0,0 +1,27 @@
+import { createCliRenderer, type CliRenderer, type CliRendererConfig } from "@opentui/core"
+import { SimulationActions } from "./actions"
+import { SimulationRenderer } from "./renderer"
+import { SimulationServer } from "./server"
+
+/**
+ * Simulation-mode renderer entry point.
+ *
+ * Creates the renderer (fake when OPENCODE_SIMULATION_RENDERER=fake, the
+ * normal visible renderer otherwise) and starts the simulation control
+ * server against it. The server stops when the renderer is destroyed, so the
+ * caller only manages the renderer lifecycle.
+ */
+export async function createSimulation(options: CliRendererConfig): Promise<CliRenderer> {
+  const renderer =
+    process.env.OPENCODE_SIMULATION_RENDERER === "fake"
+      ? await SimulationRenderer.create(options)
+      : await createCliRenderer(options)
+  const server = SimulationServer.start(SimulationActions.createHarness(renderer))
+  if (server) {
+    process.stderr.write(`opencode simulation websocket: ${server.url}\n`)
+    renderer.once("destroy", () => server.stop())
+  }
+  return renderer
+}
+
+export * as Simulation from "./simulation"