fix(protocol): expose MCP tool change events (#35373)

packages/protocol/test/event.test.ts

@@ -0,0 +1,23 @@
+import { expect, test } from "bun:test"
+import { Event } from "@opencode-ai/schema/event"
+import { AbsolutePath } from "@opencode-ai/schema/schema"
+import { DateTime, Schema } from "effect"
+import { OpenCodeEvent } from "../src/groups/event.js"
+
+test("encodes MCP tool changes emitted by the server", () => {
+  expect(
+    Schema.encodeSync(OpenCodeEvent)({
+      id: Event.ID.make("evt_test"),
+      created: DateTime.makeUnsafe(0),
+      type: "mcp.tools.changed",
+      location: { directory: AbsolutePath.make("/tmp") },
+      data: { server: "example" },
+    }),
+  ).toEqual({
+    id: "evt_test",
+    created: 0,
+    type: "mcp.tools.changed",
+    location: { directory: "/tmp" },
+    data: { server: "example" },
+  })
+})