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/panels/agent-panel.tsx

@@ -1270,7 +1270,7 @@ const AgentStreamSection = memo(function AgentStreamSection({
       ref={streamViewRef}
       agentId={agent.id}
       serverId={serverId}
-      agent={agent}
+      context={agent}
       streamItems={streamItems}
       pendingPermissions={pendingPermissions}
       routeBottomAnchorRequest={routeBottomAnchorRequest}
@@ -1364,7 +1364,7 @@ function ActiveAgentComposer({
     { initialIsBelow: isCompactFormFactor },
   );
   const paneContext = usePaneContext();
-  const { workspaceId, tabId, retargetCurrentTab } = paneContext;
+  const { workspaceId, tabId, retargetCurrentTab, openTab } = paneContext;
   const { archiveAgent } = useArchiveAgent();
   const closeWorkspaceTab = useWorkspaceLayoutStore((state) => state.closeTab);
   const hideWorkspaceAgent = useWorkspaceLayoutStore((state) => state.hideAgent);
@@ -1382,6 +1382,12 @@ function ActiveAgentComposer({
     },
     [serverId],
   );
+  const handleOpenProviderSubagent = useCallback(
+    (parentAgentId: string, subagentId: string) => {
+      openTab({ kind: "provider_subagent", parentAgentId, subagentId });
+    },
+    [openTab],
+  );
   const handleArchiveSubagent = useArchiveSubagent({ serverId });
   const handleDetachSubagent = useDetachSubagent({ serverId });
   const workspaceAttachmentScopeKey = useWorkspaceAttachmentScopeKey({
@@ -1482,6 +1488,7 @@ function ActiveAgentComposer({
       <SubagentsTrack
         rows={subagentRows}
         onOpenSubagent={handleOpenSubagent}
+        onOpenProviderSubagent={handleOpenProviderSubagent}
         onArchiveSubagent={handleArchiveSubagent}
         onDetachSubagent={canDetachSubagents ? handleDetachSubagent : undefined}
       />