refactor(core): move models.dev into core (#27347)

packages/core/src/instance-layer.ts

@@ -0,0 +1,12 @@
+import { Layer, LayerMap } from "effect"
+import { Instance } from "./instance"
+import { Catalog } from "./catalog"
+import { PluginBoot } from "./plugin/boot"
+
+export class InstanceServiceMap extends LayerMap.Service<InstanceServiceMap>()("@opencode/example/InstanceServiceMap", {
+  lookup: (ref: Instance.Ref) => {
+    const instance = Layer.succeed(Instance.Service, Instance.Service.of(ref))
+    return Layer.mergeAll(Catalog.defaultLayer, PluginBoot.defaultLayer).pipe(Layer.provide(instance))
+  },
+  idleTimeToLive: "5 minutes",
+}) {}