feat(core): bootstrap packages/server and document extraction plan (#22492)

packages/server/src/definition/api.ts

@@ -0,0 +1,6 @@
+import type { ServerApi } from "../types.js"
+
+export const api: ServerApi = {
+  name: "opencode",
+  groups: [],
+}

packages/server/src/definition/index.ts

@@ -0,0 +1 @@
+export { api } from "./api.js"