fix: show latest reply age in active thread rows

apps/mobile/src/features/threads/threadListV2.test.ts

@@ -1562,6 +1562,30 @@ describe("buildThreadListV2ListItems row-state stamps", () => {
   });
   const allEnvironments = new Set<EnvironmentId>([environmentId]);
 
+  it("ages a read row from its latest reply", () => {
+    using _timers = { [Symbol.dispose]: () => vi.useRealTimers() };
+    vi.useFakeTimers({ now: BASE_MS });
+    const label = (latestUserMessageAt: string, completedAt: string) => {
+      const thread = makeThread({
+        id: ThreadId.make("stamp-read"),
+        title: "stamp read",
+        latestUserMessageAt,
+        lastVisitedAt: isoAt(BASE_MS),
+        latestRun: {
+          runId: RunId.make("stamp-read-run"),
+          status: "completed",
+          requestedAt: latestUserMessageAt,
+          startedAt: latestUserMessageAt,
+          completedAt,
+          assistantMessageId: null,
+        },
+      });
+      const row = buildTickList([thread], BASE_MS, [])[0]!;
+      return row.type === "v2-thread" ? row.timeLabel : null;
+    };
+    expect(label(isoAt(BASE_MS - 40 * MINUTE_MS), isoAt(BASE_MS - 2 * MINUTE_MS))).toBe("2m");
+  });
+
   it("stamps queued outbox messages onto the matching row and notices removal", () => {
     const queued = buildTickList([readyThread, settledThread], BASE_MS, [], {
       queuedThreadKeys: new Set([`${environmentId}:stamp-ready`]),

apps/mobile/src/features/threads/threadListV2.ts

@@ -25,6 +25,7 @@ import {
 import {
   sortActiveThreadsByOrderKey,
   resolveSettledThreadTimestamp,
+  resolveThreadActivityTimestamp,
   sortPinnedThreadsByOrderKey,
   sortSettledThreads,
 } from "@t3tools/client-runtime/state/thread-sort";
@@ -513,7 +514,7 @@ function resolveThreadListV2ItemTimeLabel(
   const settledTimestamp =
     variant === "slim" && !snoozed ? resolveSettledThreadTimestamp(thread) : null;
   return relativeTime(
-    settledTimestamp ?? thread.latestUserMessageAt ?? thread.updatedAt ?? thread.createdAt,
+    settledTimestamp ?? resolveThreadActivityTimestamp(thread) ?? thread.createdAt,
   );
 }
 

apps/web/src/components/sidebar/SidebarThreadRow.tsx

@@ -13,7 +13,10 @@ import {
   QUEUED_TURN_START_GRACE_MS,
 } from "@t3tools/client-runtime/state/thread-settled";
 import { formatDiffCount } from "@t3tools/client-runtime/diff-count";
-import { resolveSettledThreadTimestamp } from "@t3tools/client-runtime/state/thread-sort";
+import {
+  resolveSettledThreadTimestamp,
+  resolveThreadActivityTimestamp,
+} from "@t3tools/client-runtime/state/thread-sort";
 import { type EnvironmentThreadSearchMatch } from "@t3tools/client-runtime/state/thread-search";
 import {
   formatWorkingDurationLabel,
@@ -145,10 +148,6 @@ function RelativeTimeLabel(props: { timestamp: string | null }) {
       );
 }
 
-function threadTimeTimestamp(thread: SidebarThreadSummary): string {
-  return thread.latestUserMessageAt ?? thread.updatedAt;
-}
-
 function JumpHintBadge(props: { label: string }) {
   return (
     <Kbd aria-hidden data-jump-hint>
@@ -1318,7 +1317,7 @@ const SidebarThreadRow = memo(function SidebarThreadRow(props: SidebarThreadRowP
                           timestamp={
                             variantAction === "unsettle"
                               ? resolveSettledThreadTimestamp(thread)
-                              : threadTimeTimestamp(thread)
+                              : resolveThreadActivityTimestamp(thread)
                           }
                         />
                       </span>
@@ -1513,7 +1512,7 @@ const SidebarThreadRow = memo(function SidebarThreadRow(props: SidebarThreadRowP
                         </span>
                       )
                     ) : (
-                      <RelativeTimeLabel timestamp={threadTimeTimestamp(thread)} />
+                      <RelativeTimeLabel timestamp={resolveThreadActivityTimestamp(thread)} />
                     )}
                   </span>
                   {props.settlementSupported || showSnoozeButton || hasUnsentDraft ? (
@@ -1752,7 +1751,7 @@ export const SidebarSearchResultRow = memo(function SidebarSearchResultRow(props
                 />
               </span>
               <span className="w-8 shrink-0 text-right text-xs text-muted-foreground/55 tabular-nums">
-                <RelativeTimeLabel timestamp={threadTimeTimestamp(thread)} />
+                <RelativeTimeLabel timestamp={resolveThreadActivityTimestamp(thread)} />
               </span>
             </span>
             {props.searchMatch ? (

packages/client-runtime/src/state/threadSort.ts

@@ -27,7 +27,12 @@ export function resolveSettledThreadTimestamp(thread: SettledThreadTimestampInpu
   if (thread.settledAt != null && toSortableTimestamp(thread.settledAt) !== null) {
     return thread.settledAt;
   }
+  return resolveThreadActivityTimestamp(thread);
+}
 
+export function resolveThreadActivityTimestamp(
+  thread: Pick<EnvironmentThreadShell, "latestUserMessageAt" | "latestRun" | "updatedAt">,
+): string | null {
   let latest: string | null = null;
   let latestMs = Number.NEGATIVE_INFINITY;
   for (const candidate of [