fix(cli): display correct model for sub-agents in sessions list (#18660)

Merged via /review-pr -> /prepare-pr -> /merge-pr.

Prepared head SHA: ba54c5a351
Co-authored-by: robbyczgw-cla <239660374+robbyczgw-cla@users.noreply.github.com>
Co-authored-by: gumadeiras <5599352+gumadeiras@users.noreply.github.com>
Reviewed-by: @gumadeiras

src/gateway/sessions-patch.ts

@@ -1,7 +1,11 @@
 import { randomUUID } from "node:crypto";
 import { resolveDefaultAgentId } from "../agents/agent-scope.js";
 import type { ModelCatalogEntry } from "../agents/model-catalog.js";
-import { resolveAllowedModelRef, resolveDefaultModelForAgent } from "../agents/model-selection.js";
+import {
+  resolveAllowedModelRef,
+  resolveDefaultModelForAgent,
+  resolveSubagentConfiguredModelSelection,
+} from "../agents/model-selection.js";
 import { normalizeGroupActivation } from "../auto-reply/group-activation.js";
 import {
   formatThinkingLevels,
@@ -70,6 +74,9 @@ export async function applySessionsPatchToStore(params: {
   const parsedAgent = parseAgentSessionKey(storeKey);
   const sessionAgentId = normalizeAgentId(parsedAgent?.agentId ?? resolveDefaultAgentId(cfg));
   const resolvedDefault = resolveDefaultModelForAgent({ cfg, agentId: sessionAgentId });
+  const subagentModelHint = isSubagentSessionKey(storeKey)
+    ? resolveSubagentConfiguredModelSelection({ cfg, agentId: sessionAgentId })
+    : undefined;
 
   const existing = store[storeKey];
   const next: SessionEntry = existing
@@ -298,7 +305,7 @@ export async function applySessionsPatchToStore(params: {
         catalog,
         raw: trimmed,
         defaultProvider: resolvedDefault.provider,
-        defaultModel: resolvedDefault.model,
+        defaultModel: subagentModelHint ?? resolvedDefault.model,
       });
       if ("error" in resolved) {
         return invalid(resolved.error);