fix(session): align OpenAI response stream fixtures

Author: kitlangton

packages/llm/src/schema/events.ts

@@ -222,6 +222,9 @@ const llmEventTagged = Schema.Union([
 ]).pipe(Schema.toTaggedUnion("type"))
 
 type WithID<Event extends { readonly id: unknown }, ID> = Omit<Event, "type" | "id"> & { readonly id: ID | string }
+type WithUsage<Event extends { readonly usage?: Usage }> = Omit<Event, "type" | "usage"> & {
+  readonly usage?: Usage | ConstructorParameters<typeof Usage>[0]
+}
 
 const responseID = (value: ResponseID | string) => ResponseID.make(value)
 const contentBlockID = (value: ContentBlockID | string) => ContentBlockID.make(value)
@@ -252,8 +255,10 @@ export const LLMEvent = Object.assign(llmEventTagged, {
   toolCall: (input: WithID<ToolCall, ToolCallID>) => ToolCall.make({ ...input, id: toolCallID(input.id) }),
   toolResult: (input: WithID<ToolResult, ToolCallID>) => ToolResult.make({ ...input, id: toolCallID(input.id) }),
   toolError: (input: WithID<ToolError, ToolCallID>) => ToolError.make({ ...input, id: toolCallID(input.id) }),
-  stepFinish: StepFinish.make,
-  requestFinish: RequestFinish.make,
+  stepFinish: (input: WithUsage<StepFinish>) =>
+    StepFinish.make({ ...input, usage: input.usage instanceof Usage ? input.usage : new Usage(input.usage ?? {}) }),
+  requestFinish: (input: WithUsage<RequestFinish>) =>
+    RequestFinish.make({ ...input, usage: input.usage instanceof Usage ? input.usage : new Usage(input.usage ?? {}) }),
   providerError: ProviderErrorEvent.make,
   is: {
     requestStart: llmEventTagged.guards["request-start"],

packages/opencode/test/session/llm.test.ts

@@ -581,6 +581,18 @@ describe("session.llm.stream", () => {
           service_tier: null,
         },
       },
+      {
+        type: "response.output_item.added",
+        output_index: 0,
+        item: { type: "message", id: "item-1", status: "in_progress", role: "assistant", content: [] },
+      },
+      {
+        type: "response.content_part.added",
+        item_id: "item-1",
+        output_index: 0,
+        content_index: 0,
+        part: { type: "output_text", text: "", annotations: [] },
+      },
       {
         type: "response.output_text.delta",
         item_id: "item-1",
@@ -694,6 +706,18 @@ describe("session.llm.stream", () => {
           service_tier: null,
         },
       },
+      {
+        type: "response.output_item.added",
+        output_index: 0,
+        item: { type: "message", id: "item-data-url", status: "in_progress", role: "assistant", content: [] },
+      },
+      {
+        type: "response.content_part.added",
+        item_id: "item-data-url",
+        output_index: 0,
+        content_index: 0,
+        part: { type: "output_text", text: "", annotations: [] },
+      },
       {
         type: "response.output_text.delta",
         item_id: "item-data-url",