refactor(cli): unify server endpoint handling

packages/cli/test/fixture/standalone-owner.ts

@@ -1,4 +1,5 @@
 import { Effect } from "effect"
+import { Service } from "@opencode-ai/client/effect"
 import path from "node:path"
 import { Standalone } from "../../src/services/standalone"
 
@@ -7,9 +8,11 @@ process.argv[1] = path.join(import.meta.dir, "../../src/index.ts")
 await Effect.runPromise(
   Effect.scoped(
     Effect.gen(function* () {
-      const transport = yield* Standalone.transport()
-      const response = yield* Effect.promise(() => fetch(new URL("/api/health", transport.url), { headers: transport.headers }))
-      console.log(`${transport.pid} ${transport.url} ${response.status}`)
+      const endpoint = yield* Standalone.start()
+      const response = yield* Effect.promise(() =>
+        fetch(new URL("/api/health", endpoint.url), { headers: Service.headers(endpoint) }),
+      )
+      console.log(`${endpoint.pid} ${endpoint.url} ${response.status}`)
       return yield* Effect.never
     }),
   ),