feat(cli): add effect cli scaffold

packages/cli/src/index.ts

@@ -0,0 +1,15 @@
+#!/usr/bin/env bun
+
+import * as NodeRuntime from "@effect/platform-node/NodeRuntime"
+import * as NodeServices from "@effect/platform-node/NodeServices"
+import * as Effect from "effect/Effect"
+import * as Command from "effect/unstable/cli/Command"
+
+const cli = Command.make("opencode", {}, () => Effect.void).pipe(
+  Command.withDescription("OpenCode command line interface"),
+)
+
+Command.run(cli, { version: "local" }).pipe(
+  Effect.provide(NodeServices.layer),
+  NodeRuntime.runMain,
+)