Show provider subagents in the subagents track (#2013)

* Add provider-owned subagent stream contract

* OpenCode provider: detect child sessions, attach adopted children to the hosting server, synthesize external turns

- Emit internal provider_child_session_detected / provider_session_deleted stream events from the global event stream (before the no-active-turn gate), including BFS hydration of existing descendants on subscribe
- Track child sessions in a registry mapping child session id -> hosting server url; resumeSession attaches via acquireExisting() so adopted children share the parent's server generation and keep receiving live events
- Synthesize external turns for adopted (externally driven) sessions so timeline, tool calls, and permission requests stream without a Paseo-initiated prompt
- Honor launchContext.env in resumeSession (acquireDedicated parity with createSession)
- Stop folding child tool parts into the parent's sub_agent action log; the parent row stays as a pointer

* Render provider subagents in workspace timelines

* fix provider subagent timeline reliability

* fix provider subagent lifecycle edge cases

* fix provider subagent event fidelity

* Fix provider subagent history fidelity

* Fix restored provider subagent state

* Fix provider subagent visibility edges

* Restore provider subagent timelines

* Page provider subagent history

* Forward subagent questions reliably

* fix(subagents): preserve OpenCode child context

* fix(subagents): harden provider timeline routing

* fix(subagents): preserve provider page continuity

* fix(subagents): retain live child prompts

---------

Co-authored-by: Omer <639682+omercnet@users.noreply.github.com>

packages/app/src/subagents/select.test.ts

@@ -1,6 +1,7 @@
 import type { DaemonClient } from "@getpaseo/client/internal/daemon-client";
 import { afterEach, describe, expect, it } from "vitest";
-import { selectSubagentsForParent } from "./select";
+import { selectProviderSubagentsForParent, selectSubagentsForParent } from "./select";
+import { useProviderSubagentStore } from "./provider-store";
 import { useSessionStore, type Agent } from "@/stores/session-store";
 
 const SERVER_ID = "server-1";
@@ -58,9 +59,37 @@ function setAgents(agents: Agent[]): void {
 
 afterEach(() => {
   useSessionStore.getState().clearSession(SERVER_ID);
+  useProviderSubagentStore.setState({ descriptors: new Map(), timelines: new Map() });
 });
 
 describe("selectSubagentsForParent", () => {
+  it("hides cached provider children when the host does not support them", () => {
+    useProviderSubagentStore.getState().applyUpdate(SERVER_ID, {
+      kind: "upsert",
+      subagent: {
+        id: "provider-child",
+        parentAgentId: "parent-a",
+        provider: "codex",
+        title: "Provider child",
+        description: null,
+        status: "completed",
+        createdAt: "2026-03-08T10:01:00.000Z",
+        updatedAt: "2026-03-08T10:02:00.000Z",
+        toolCallId: "call-1",
+      },
+    });
+    const params = { serverId: SERVER_ID, parentAgentId: "parent-a" };
+
+    expect(
+      selectProviderSubagentsForParent(useProviderSubagentStore.getState(), params, false),
+    ).toEqual([]);
+    expect(
+      selectProviderSubagentsForParent(useProviderSubagentStore.getState(), params, true).map(
+        (row) => row.id,
+      ),
+    ).toEqual(["provider-child"]);
+  });
+
   it("returns only non-archived children for the requested parent", () => {
     setAgents([
       makeAgent({ id: "parent-a" }),
@@ -194,6 +223,7 @@ describe("selectSubagentsForParent", () => {
 
     expect(rows).toEqual([
       {
+        kind: "paseo",
         id: "child",
         provider: "claude",
         title: "Review child",
@@ -205,6 +235,7 @@ describe("selectSubagentsForParent", () => {
     expect(Object.keys(rows[0] ?? {}).sort()).toEqual([
       "createdAt",
       "id",
+      "kind",
       "provider",
       "requiresAttention",
       "status",