fix(ui): resolve session thinking defaults

ui/src/ui/views/sessions.test.ts

@@ -5,12 +5,15 @@ import { describe, expect, it, vi } from "vitest";
 import type { SessionsListResult } from "../types.ts";
 import { renderSessions, type SessionsProps } from "./sessions.ts";
 
-function buildResult(session: SessionsListResult["sessions"][number]): SessionsListResult {
+function buildResult(
+  session: SessionsListResult["sessions"][number],
+  defaults?: Partial<SessionsListResult["defaults"]>,
+): SessionsListResult {
   return {
     ts: Date.now(),
     path: "(multiple)",
     count: 1,
-    defaults: { modelProvider: null, model: null, contextTokens: null },
+    defaults: { modelProvider: null, model: null, contextTokens: null, ...defaults },
     sessions: [session],
   };
 }
@@ -268,6 +271,41 @@ describe("sessions view", () => {
     ).toBe("Override: adaptive");
   });
 
+  it("labels inherited thinking from list defaults when lightweight rows omit row defaults", async () => {
+    const container = document.createElement("div");
+    render(
+      renderSessions(
+        buildProps(
+          buildResult(
+            {
+              key: "agent:main:main",
+              kind: "direct",
+              updatedAt: Date.now(),
+            },
+            {
+              modelProvider: "openai-codex",
+              model: "gpt-5.5",
+              thinkingDefault: "high",
+              thinkingLevels: [
+                { id: "off", label: "off" },
+                { id: "high", label: "high" },
+              ],
+            },
+          ),
+        ),
+      ),
+      container,
+    );
+    await Promise.resolve();
+
+    const thinking = container.querySelector("tbody select") as HTMLSelectElement | null;
+    expect(thinking?.value).toBe("");
+    expect(thinking?.options[0]?.textContent?.trim()).toBe("Inherited: high");
+    expect(Array.from(thinking?.options ?? []).map((option) => option.textContent?.trim())).toEqual(
+      ["Inherited: high", "Off", "Override: high"],
+    );
+  });
+
   it("keeps legacy binary thinking labels patching canonical ids", async () => {
     const container = document.createElement("div");
     const onPatch = vi.fn();

ui/src/ui/views/sessions.ts

@@ -92,16 +92,37 @@ function getAgentIdentity(
     : null;
 }
 
+function rowMatchesSessionDefaults(
+  row: GatewaySessionRow,
+  defaults: SessionsListResult["defaults"] | undefined,
+): boolean {
+  return (
+    (!row.modelProvider || row.modelProvider === defaults?.modelProvider) &&
+    (!row.model || row.model === defaults?.model)
+  );
+}
+
 function resolveThinkLevelOptions(
   row: GatewaySessionRow,
+  defaults?: SessionsListResult["defaults"],
 ): readonly { value: string; label: string }[] {
-  const defaultLabel = formatInheritedThinkingLabel(row.thinkingDefault);
+  const sessionModelMatchesDefaults = rowMatchesSessionDefaults(row, defaults);
+  const defaultLabel = formatInheritedThinkingLabel(
+    row.thinkingDefault ?? (sessionModelMatchesDefaults ? defaults?.thinkingDefault : undefined),
+  );
   const options: readonly GatewayThinkingLevelOption[] = row.thinkingLevels?.length
     ? row.thinkingLevels
-    : (row.thinkingOptions?.length ? row.thinkingOptions : DEFAULT_THINK_LEVELS).map((label) => ({
+    : sessionModelMatchesDefaults && defaults?.thinkingLevels?.length
-        id: normalizeThinkingOptionValue(label),
+      ? defaults.thinkingLevels
-        label,
+      : (row.thinkingOptions?.length
-      }));
+          ? row.thinkingOptions
+          : sessionModelMatchesDefaults && defaults?.thinkingOptions?.length
+            ? defaults.thinkingOptions
+            : DEFAULT_THINK_LEVELS
+        ).map((label) => ({
+          id: normalizeThinkingOptionValue(label),
+          label,
+        }));
   return [
     { value: "", label: defaultLabel },
     ...options.map((option) => ({
@@ -684,7 +705,10 @@ function renderRows(row: GatewaySessionRow, props: SessionsProps) {
   const updated = row.updatedAt ? formatRelativeTimestamp(row.updatedAt) : t("common.na");
   const rawThinking = row.thinkingLevel ?? "";
   const thinking = rawThinking ? normalizeThinkingOptionValue(rawThinking) : "";
-  const thinkLevels = withCurrentLabeledOption(resolveThinkLevelOptions(row), thinking);
+  const thinkLevels = withCurrentLabeledOption(
+    resolveThinkLevelOptions(row, props.result?.defaults),
+    thinking,
+  );
   const fastMode = row.fastMode === true ? "on" : row.fastMode === false ? "off" : "";
   const fastLevels = withCurrentLabeledOption(buildFastLevelOptions(), fastMode);
   const verbose = row.verboseLevel ?? "";