fix(sdk): preserve V2Event name for SSE streams

packages/opencode/test/server/httpapi-public-openapi.test.ts

@@ -10,6 +10,8 @@ type OpenApiSchema = {
   readonly enum?: readonly unknown[]
   readonly properties?: Record<string, OpenApiSchema>
   readonly required?: readonly string[]
+  readonly contentSchema?: OpenApiSchema
+  readonly contentMediaType?: string
 }
 type OpenApiResponse = {
   readonly description?: string
@@ -99,6 +101,21 @@ describe("PublicApi OpenAPI v2 errors", () => {
     })
   })
 
+  test("names the v2 event union without the SSE string wrapper collision", () => {
+    const spec = OpenApi.fromApi(PublicApi) as OpenApiSpec
+
+    expect(spec.components.schemas.V2Event1).toBeUndefined()
+    expect(spec.components.schemas.V2Event?.anyOf?.length).toBeGreaterThan(0)
+    expect(spec.components.schemas.V2EventStream).toMatchObject({
+      type: "string",
+      contentMediaType: "application/json",
+      contentSchema: { $ref: "#/components/schemas/V2Event" },
+    })
+    expect(spec.paths["/api/event"]?.get?.responses?.["200"]?.content?.["text/event-stream"]?.schema).toEqual({
+      $ref: "#/components/schemas/V2Event",
+    })
+  })
+
   test("preserves /api auth responses", () => {
     const spec = OpenApi.fromApi(PublicApi) as OpenApiSpec