refactor(schema): extract public event definitions (#33579)

packages/core/test/legacy-event-schema.test.ts

@@ -0,0 +1,16 @@
+import { describe, expect, test } from "bun:test"
+import { SessionV1 as Wire } from "@opencode-ai/schema/session-v1"
+import { SessionV1 } from "../src/v1/session"
+
+describe("legacy event schema compatibility", () => {
+  test("Core references canonical SessionV1 definitions", () => {
+    expect(SessionV1.Event.Created).toBe(Wire.Event.Created)
+    expect(SessionV1.Event.PartUpdated).toBe(Wire.Event.PartUpdated)
+  })
+
+  test("Core retains NamedError constructor identity", () => {
+    const error = new SessionV1.APIError({ message: "failed", isRetryable: false })
+    expect(error).toBeInstanceOf(SessionV1.APIError)
+    expect(error.toObject()).toEqual({ name: "APIError", data: { message: "failed", isRetryable: false } })
+  })
+})