fix(opencode): show model details on v2 subagent rows (#7799)

The v2 child descriptor omitted the session's presentation facts, leaving
completed children with title-only rows. Reuse the existing subtitle
formatter for both live updates and reconciliation.

Co-authored-by: paseo-bot[bot] <266920839+paseo-bot[bot]@users.noreply.github.com>
Co-authored-by: Davin <128177533+Davnn1@users.noreply.github.com>

packages/server/src/server/agent/providers/opencode/v2/children.test.ts

@@ -0,0 +1,80 @@
+import type { SessionInfo } from "@opencode/client";
+import { describe, expect, test } from "vitest";
+
+import type { AgentStreamEvent } from "../../../agent-sdk-types.js";
+import { V2Harness } from "../test-utils/v2-harness.js";
+import { SessionChildren } from "./children.js";
+
+function setup() {
+  const harness = new V2Harness();
+  const child: SessionInfo = {
+    ...harness.info,
+    id: "child",
+    parentID: "session",
+    title: "Check the worker model",
+    agent: "worker",
+    model: { providerID: "test", id: "worker-model", variant: "xhigh" },
+    tokens: { input: 10000, output: 3000, reasoning: 2000, cache: { read: 3000, write: 800 } },
+  };
+  harness.api.session.list = async (input) => ({
+    data: input?.parentID === "session" ? [child] : [],
+    cursor: {},
+  });
+  harness.api.session.get = async () => child;
+  const events: AgentStreamEvent[] = [];
+  const children = new SessionChildren({
+    client: () => harness.api,
+    id: "session",
+    emit: (event) => events.push(event),
+    reconcilePermissions: async () => {},
+  });
+  const upserts = () =>
+    events.flatMap((event) =>
+      event.type === "provider_subagent" && event.event.type === "upsert" ? [event.event] : [],
+    );
+  return { children, child, upserts };
+}
+
+describe("OpenCode v2 child presentation", () => {
+  test("restores agent, model, variant and all token categories in the child subtitle", async () => {
+    const { children, upserts } = setup();
+    await children.reconcile("session");
+    expect(upserts()).toEqual([
+      expect.objectContaining({
+        id: "child",
+        title: "Check the worker model",
+        parentSubagentId: null,
+        status: "completed",
+        subtitle: "worker · worker-model · Extra High · 18.8k tokens",
+      }),
+    ]);
+    await children.reconcile("session");
+    expect(upserts()).toHaveLength(1);
+  });
+
+  test("publishes changed child facts on live events even when its timestamp is unchanged", async () => {
+    const { children, child, upserts } = setup();
+    await children.observe({ id: "created", created: 1, type: "session.created", data: child });
+    child.model = { providerID: "test", id: "next-model", variant: "low" };
+    child.tokens.output += 1200;
+    await children.observe({
+      id: "finished",
+      created: 2,
+      type: "session.execution.succeeded",
+      durable: { aggregateID: "child", seq: 1, version: 1 },
+      data: { sessionID: "child" },
+    });
+    expect(upserts().map((event) => event.subtitle)).toEqual([
+      "worker · worker-model · Extra High · 18.8k tokens",
+      "worker · next-model · Low · 20k tokens",
+    ]);
+  });
+
+  test("keeps available agent information before a child has a model or token usage", async () => {
+    const { children, child, upserts } = setup();
+    delete child.model;
+    child.tokens = { input: 0, output: 0, reasoning: 0, cache: { read: 0, write: 0 } };
+    await children.reconcile("session");
+    expect(upserts()[0]).toMatchObject({ title: "Check the worker model", subtitle: "worker" });
+  });
+});

packages/server/src/server/agent/providers/opencode/v2/children.ts

@@ -7,6 +7,7 @@ import type { AgentStreamEvent } from "../../../agent-sdk-types.js";
 import type { ProviderSubagentInputEvent } from "../../../provider-subagents/store.js";
 
 import { messages } from "./history.js";
+import { buildOpenCodeSubagentSubtitle } from "../subagent-presentation.js";
 
 import type { V2Api } from "./api.js";
 interface ChildrenOptions {
@@ -65,11 +66,23 @@ export class SessionChildren {
     if (active[info.id]) status = "running";
     else if (info.outcome === "failed") status = "failed";
     else if (info.outcome === "interrupted") status = "canceled";
+    const subtitle = buildOpenCodeSubagentSubtitle({
+      agentName: info.agent,
+      modelId: info.model?.id,
+      variant: info.model?.variant,
+      totalTokens:
+        info.tokens.input +
+        info.tokens.output +
+        info.tokens.reasoning +
+        info.tokens.cache.read +
+        info.tokens.cache.write,
+    });
     const presentation: ProviderSubagentInputEvent = {
       type: "upsert",
       id: info.id,
       parentSubagentId: info.parentID === this.options.id ? null : info.parentID,
       title: info.title ?? null,
+      ...(subtitle ? { subtitle } : {}),
       status,
       cwd: info.location.directory,
       timestamp: new Date(info.time.updated).toISOString(),