Add Effect-native core event system (#27415)

packages/core/src/location.ts

@@ -0,0 +1,11 @@
+import { Context, Schema } from "effect"
+
+export * as Location from "./location"
+
+export const Ref = Schema.Struct({
+  directory: Schema.String,
+  workspaceID: Schema.optional(Schema.String),
+}).annotate({ identifier: "Location.Ref" })
+export type Ref = typeof Ref.Type
+
+export class Service extends Context.Service<Service, Ref>()("@opencode/Location") {}