perf(client): cut needless polling for local users

- ConversationView: an ended session (SessionDetail, SessionReplay pass
  `ended`) polls its transcript every 60 s instead of 3 s and stops
  rescanning sub-agents; new_event, reconnect and show still fetch at once.
- Workspace: GET /api/run follows run-moving WS messages (lane run
  columns, session created/status change, runs_interrupted) with a 30 s
  fallback, instead of a blind 5 s poll.
- StatusBar: session counts re-read only when a session's
  status/waiting/archived state changes (60 s fallback); costs re-read at
  most every 30 s while work is happening and every 2 min otherwise.
- Dashboard recent activity: 60 s safety poll (was 10 s) plus remote
  import messages; WS still prepends new events.
- New lib/sessionChange.ts matcher with tests.

client/src/components/StatusBar.tsx

@@ -9,8 +9,12 @@
  * Workspace page, the open workspace's total (`?lane=` on the same call: the
  * sessions it owns) and the shown session's (`GET /api/pricing/cost/:id` for
  * the URL's `session`, or the focused pane's session from the page's run poll,
- * `LIVE_RUNS_EVENT`), all re-read every 30 s while the tab is visible and
- * whenever the URL names another workspace or session. Each figure carries its
+ * `LIVE_RUNS_EVENT`), all re-read at once whenever the URL names another
+ * workspace or session, then at most every 30 s while events or session
+ * updates arrive (spend only moves with work) and every 2 min otherwise, while
+ * the tab is visible. The session counts re-read only when a session is
+ * created or its status / waiting / archived state changes (every 60 s
+ * otherwise). Each figure carries its
  * token total, and hovering it lists tokens and cost per model. At the right
  * end, the plan quota spent per native tool (`GET /api/pricing/quota`, every
  * 5 min while visible; a click forces a re-read): one "N% used" chip per tool —
@@ -31,9 +35,15 @@ import { fmt, fmtCostFull, formatModelName, timeAgo } from "../lib/format";
 import { AiToolIcon } from "./AiToolIcon";
 import { useLiveRefresh } from "../hooks/useLiveRefresh";
 import { useSpin } from "../hooks/useSpin";
+import { sessionChangeMatcher } from "../lib/sessionChange";
 import { LIVE_RUNS_EVENT, selectedFrom } from "./WorkspaceTree";
 
+/** Spend moves only with work: at most this often while events arrive… */
 const COST_POLL_MS = 30_000;
+/** …and this often regardless (date rollover, budget period, a missed frame). */
+const COST_FALLBACK_MS = 120_000;
+/** The counts' safety poll; session frames that change a count drive the rest. */
+const COUNTS_FALLBACK_MS = 60_000;
 const QUOTA_POLL_MS = 5 * 60_000;
 const QUOTA_TOOL_LABEL: Record<ToolQuota["id"], string> = {
   claude: "Claude",
@@ -384,51 +394,57 @@ export function StatusBar({
       .catch(() => undefined);
   }, []);
   useEffect(loadCounts, [loadCounts]);
-  useLiveRefresh(loadCounts, {
-    intervalMs: 15_000,
-    match: (msg) => msg.type === "session_updated" || msg.type === "session_created",
-  });
+  // Only a frame that moves a session between the counted states (a new
+  // session, a status / waiting / archived change) re-reads: a session row is
+  // re-broadcast on almost every hook.
+  const [countsChanged] = useState(() => sessionChangeMatcher());
+  useLiveRefresh(loadCounts, { intervalMs: COUNTS_FALLBACK_MS, match: countsChanged });
 
+  // Bumped on every lane/session switch: an answer for the previous one is dropped.
+  const costGen = useRef(0);
+  const loadCosts = useCallback(() => {
+    const gen = costGen.current;
+    const live = () => gen === costGen.current;
+    api.pricing
+      .totalCost({ date: localDate() })
+      .then((r) => live() && setToday(r))
+      .catch(() => undefined);
+    api.budgets
+      .status()
+      .then(({ budgets }) => {
+        const hit = budgets.filter((b) => b.crossed.length > 0).sort((a, b) => b.pct - a.pct);
+        if (live()) setBudget(hit[0] ?? null);
+      })
+      .catch(() => undefined);
+    if (lane !== null) {
+      api.pricing
+        .totalCost({ lane })
+        .then((r) => live() && setLaneCost(r))
+        .catch(() => undefined);
+    }
+    if (sessionId) {
+      api.pricing
+        .sessionCost(sessionId)
+        .then((r) => live() && setSessionCost(r))
+        .catch(() => undefined);
+    }
+  }, [lane, sessionId]);
   useEffect(() => {
-    let live = true;
+    costGen.current++;
     // Another workspace or session: never show the previous one's figure.
     setLaneCost(null);
     setSessionCost(null);
-    const tick = () => {
-      if (document.visibilityState !== "visible") return;
-      api.pricing
-        .totalCost({ date: localDate() })
-        .then((r) => live && setToday(r))
-        .catch(() => undefined);
-      api.budgets
-        .status()
-        .then(({ budgets }) => {
-          const hit = budgets.filter((b) => b.crossed.length > 0).sort((a, b) => b.pct - a.pct);
-          if (live) setBudget(hit[0] ?? null);
-        })
-        .catch(() => undefined);
-      if (lane !== null) {
-        api.pricing
-          .totalCost({ lane })
-          .then((r) => live && setLaneCost(r))
-          .catch(() => undefined);
-      }
-      if (sessionId) {
-        api.pricing
-          .sessionCost(sessionId)
-          .then((r) => live && setSessionCost(r))
-          .catch(() => undefined);
-      }
-    };
-    tick();
-    const id = setInterval(tick, COST_POLL_MS);
-    document.addEventListener("visibilitychange", tick);
+    if (document.visibilityState === "visible") loadCosts();
     return () => {
-      live = false;
-      clearInterval(id);
-      document.removeEventListener("visibilitychange", tick);
+      costGen.current++;
     };
-  }, [lane, sessionId]);
+  }, [loadCosts]);
+  useLiveRefresh(loadCosts, {
+    intervalMs: COST_FALLBACK_MS,
+    throttleMs: COST_POLL_MS,
+    match: (msg) =>
+      msg.type === "new_event" || msg.type === "session_updated" || msg.type === "session_created",
+  });
 
   return (
     <footer

client/src/components/conversation/ConversationView.tsx

@@ -14,6 +14,10 @@
  * `onOpenTerminal`) and hears how full the context is (`onContext`) and
  * whether its session has started (`onNotStarted`: no row yet — the CLI may
  * be asking in the terminal, e.g. to trust the folder, which this then says).
+ * A caller that knows the session has ended passes `ended`: nothing more is
+ * being written, so the catch-up poll drops from 3 s to 60 s and the
+ * sub-agent list stops being rescanned — a `new_event` frame, a reconnect or
+ * the view being shown again still fetch the tail at once.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 /* =============================================================================
@@ -79,6 +83,9 @@ import type { TranscriptMessage, TranscriptInfo, WSMessage } from "../../lib/typ
 // hook event. A short visibility-gated poll closes that gap and also rescues
 // the conversation from missed/late WebSocket frames.
 const POLL_INTERVAL_MS = 3000;
+// An ended session writes nothing more: a slow safety poll only, in case it was
+// resumed somewhere whose frames this view missed.
+const ENDED_POLL_INTERVAL_MS = 60000;
 // Rescan the transcripts list periodically so new subagents that spawn
 // mid-session appear in the dropdown without a page reload.
 const TRANSCRIPTS_REFRESH_MS = 15000;
@@ -110,6 +117,8 @@ interface ConversationViewProps {
   onContext?: (tokens: number, model: string | null) => void;
   /** A live pane's session has no row yet: the CLI has not started it. */
   onNotStarted?: (notStarted: boolean) => void;
+  /** The session has ended (and no pane holds it): poll slowly, if at all. */
+  ended?: boolean;
 }
 
 function ConversationViewPane({
@@ -124,6 +133,7 @@ function ConversationViewPane({
   stopped = 0,
   onContext,
   onNotStarted,
+  ended = false,
 }: ConversationViewProps) {
   const { t } = useTranslation("sessions");
   const [messages, setMessages] = useState<TranscriptMessage[]>([]);
@@ -188,14 +198,18 @@ function ConversationViewPane({
       }
     }
     loadTranscripts();
-    const interval = window.setInterval(() => {
-      if (isShown(onScreen)) loadTranscripts();
-    }, TRANSCRIPTS_REFRESH_MS);
+    // An ended session spawns no new sub-agents: the load above (re-run when
+    // it ends, for the last ones) is enough.
+    const interval = ended
+      ? undefined
+      : window.setInterval(() => {
+          if (isShown(onScreen)) loadTranscripts();
+        }, TRANSCRIPTS_REFRESH_MS);
     return () => {
       cancelled = true;
       window.clearInterval(interval);
     };
-  }, [sessionId]);
+  }, [sessionId, ended]);
 
   // Sync external initialTranscriptId to internal state
   useEffect(() => {
@@ -355,9 +369,12 @@ function ConversationViewPane({
     let interval: number | null = null;
     function start() {
       if (interval !== null) return;
-      interval = window.setInterval(() => {
-        if (isShown(onScreen)) fetchNewMessages();
-      }, POLL_INTERVAL_MS);
+      interval = window.setInterval(
+        () => {
+          if (isShown(onScreen)) fetchNewMessages();
+        },
+        ended ? ENDED_POLL_INTERVAL_MS : POLL_INTERVAL_MS
+      );
     }
     function stop() {
       if (interval !== null) {
@@ -382,7 +399,7 @@ function ConversationViewPane({
       stop();
       document.removeEventListener("visibilitychange", onVisibility);
     };
-  }, [fetchNewMessages, onScreen]);
+  }, [fetchNewMessages, onScreen, ended]);
 
   // Manual refresh - surfaces a control in the toolbar so users can force
   // a sync without reloading the page.

client/src/components/lanes/SessionReplay.tsx

@@ -132,7 +132,11 @@ export function SessionReplay({
         </div>
       )}
       <div className="min-h-0 flex-1 overflow-hidden">
-        <ConversationView sessionId={sessionId} fill />
+        <ConversationView
+          sessionId={sessionId}
+          fill
+          ended={!livePane && !!session && session.status !== "active"}
+        />
       </div>
       {livePane ? (
         <div

client/src/lib/__tests__/sessionChange.test.ts

@@ -0,0 +1,34 @@
+/**
+ * @file sessionChange.test.ts
+ * @description Unit tests for `sessionChangeMatcher`: fires on a new session
+ * and on a change of the keyed columns, never on a re-broadcast that moved none.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+import { describe, expect, it } from "vitest";
+import { sessionChangeMatcher } from "../sessionChange";
+import type { WSMessage } from "../types";
+
+const msg = (type: string, data: unknown) => ({ type, data, timestamp: "" }) as WSMessage;
+
+describe("sessionChangeMatcher", () => {
+  it("fires on a new session and on a state change, not on a same-state re-broadcast", () => {
+    const m = sessionChangeMatcher();
+    expect(m(msg("session_created", { id: "a", status: "active" }))).toBe(true);
+    expect(m(msg("session_updated", { id: "a", status: "active", name: "x" }))).toBe(false);
+    expect(
+      m(msg("session_updated", { id: "a", status: "active", awaiting_input_since: "t" }))
+    ).toBe(true);
+    expect(m(msg("session_updated", { id: "a", status: "completed" }))).toBe(true);
+    expect(m(msg("session_updated", { id: "a", status: "completed", archived_at: "t" }))).toBe(
+      true
+    );
+  });
+
+  it("takes an unseen or unkeyable session as a change, and ignores other types", () => {
+    const m = sessionChangeMatcher();
+    expect(m(msg("session_updated", { id: "b", status: "active" }))).toBe(true);
+    expect(m(msg("session_updated", null))).toBe(true);
+    expect(m(msg("new_event", { session_id: "b" }))).toBe(false);
+  });
+});

client/src/lib/sessionChange.ts

@@ -0,0 +1,32 @@
+/**
+ * @file sessionChange.ts
+ * @description `session_created` / `session_updated` matcher for live-refresh
+ * callers that care about only a few session columns. A session row is
+ * re-broadcast on nearly every hook (last activity, name, tokens…), so
+ * matching the bare message types made every such frame refetch; this one
+ * fires on a new session, or when the chosen key of a session actually
+ * changed. Each call keeps its own memory of the keys it has seen.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+import type { Session, WSMessage } from "./types";
+
+/** The columns that move a session between the active / waiting / archived counts. */
+export const sessionStateKeyOf = (s: Partial<Session>): string =>
+  `${s.status}:${s.awaiting_input_since ? 1 : 0}:${s.archived_at ? 1 : 0}`;
+
+export function sessionChangeMatcher(
+  keyOf: (s: Partial<Session>) => string = sessionStateKeyOf
+): (msg: WSMessage) => boolean {
+  const seen = new Map<string, string>();
+  return (msg) => {
+    if (msg.type !== "session_created" && msg.type !== "session_updated") return false;
+    const s = msg.data as Partial<Session> | undefined;
+    // A frame we cannot key is taken as a change: refetching is the safe side.
+    if (!s || typeof s.id !== "string") return true;
+    const key = keyOf(s);
+    if (msg.type === "session_updated" && seen.get(s.id) === key) return false;
+    seen.set(s.id, key);
+    return true;
+  };
+}

client/src/pages/Dashboard.tsx

@@ -2790,9 +2790,12 @@ function RecentActivityPanel({ sessionsById }: { sessionsById: Map<string, Sessi
   useEffect(() => {
     load();
   }, [load]);
-  useLiveRefresh(load, { intervalMs: 10000 });
+  // New events arrive over the WebSocket (prepended below); a reload is only
+  // for what the socket cannot carry: a remote source's import, a gap while it
+  // was down (reconnect) or the tab hidden (shown again), and a slow safety poll.
+  useLiveRefresh(load, { intervalMs: 60000, match: isRemoteDataRefreshMessage });
 
-  // A new event is prepended at once (no reload); the poll reconciles.
+  // A new event is prepended at once (no reload); the reloads reconcile.
   useEffect(
     () =>
       eventBus.subscribe((msg: WSMessage) => {

client/src/pages/SessionDetail.tsx

@@ -1129,7 +1129,11 @@ export function SessionDetail() {
 
       {visitedTabs.has("conversation") && (
         <div hidden={activeTab !== "conversation"}>
-          <ConversationView sessionId={session.id} initialTranscriptId={pendingTranscriptId} />
+          <ConversationView
+            sessionId={session.id}
+            initialTranscriptId={pendingTranscriptId}
+            ended={session.status !== "active"}
+          />
         </div>
       )}
 

client/src/pages/Workspace.tsx

@@ -85,6 +85,9 @@ import { endRuns } from "../lib/stopSession";
 import { ContextMenu, MenuItem, useContextMenu } from "../components/ContextMenu";
 import { confirmDiscard } from "../lib/confirm";
 import { keepIfSame } from "../lib/keepIfSame";
+import { laneChangeMatcher, runKeyOf } from "../lib/laneChange";
+import { sessionChangeMatcher } from "../lib/sessionChange";
+import { useLiveRefresh } from "../hooks/useLiveRefresh";
 import { useWorkLanes } from "../hooks/useLanes";
 import { LaneConsolePane } from "../components/run/LaneConsolePane";
 import {
@@ -1044,9 +1047,10 @@ export function Workspace() {
       .catch(() => undefined);
   }, []);
 
-  // Goes through `keepIfSame`: this fires every 5 s below, and a
-  // fresh-but-identical payload would otherwise re-render the lane strip, the
-  // lane card and the whole console area on every tick for nothing.
+  // Goes through `keepIfSame`: this re-reads on run-moving messages and a
+  // fallback poll below, and a fresh-but-identical payload would otherwise
+  // re-render the lane strip, the lane card and the whole console area for
+  // nothing.
   const refreshList = useCallback(() => {
     api.run
       .list()
@@ -1061,33 +1065,30 @@ export function Workspace() {
       window.dispatchEvent(new CustomEvent(LIVE_RUNS_EVENT, { detail: activeRuns.items }));
   }, [activeRuns]);
 
-  // Background poll so the run list and history reflect external changes
-  // (server-boot reconciliation, sibling tabs, direct DB edits) even when
-  // no WS event fires. Lighter than typical WS gaps; aggressive enough that
-  // status flips appear within seconds without needing a manual refresh.
+  // The run list follows the WebSocket instead of a blind 5 s poll: a pane
+  // starting, ending or learning its session in slot 0 moves the lane's run
+  // columns (`lane_update`); an agent starting in a free tab (slots 1–9)
+  // shows as a new session, one ending as a session status change, and a pane
+  // dying under its agent as `runs_interrupted`. This page's own starts, stops
+  // and a shown terminal's exit call `refreshList` directly
+  // (`onRunsChanged`). What none of those cover — a shell tab opened or closed
+  // from another browser, server-boot reconciliation — is caught by the
+  // 30 s fallback poll, on reconnect, and when the tab is shown or focused.
+  const [laneRunChanged] = useState(() => laneChangeMatcher(runKeyOf));
+  const [sessionRunChanged] = useState(() => sessionChangeMatcher((s) => `${s.status}`));
   useEffect(() => {
     refreshList();
-    const tick = setInterval(() => {
-      // Hidden tab: skip; the visibility handler below re-reads on show.
-      if (document.visibilityState === "visible") refreshList();
-    }, 5000);
-    return () => clearInterval(tick);
   }, [refreshList]);
-
-  // Refresh whenever the tab regains focus / visibility - typical when the
-  // user comes back from running `claude` in a terminal and wants to see the
-  // current state of every run without waiting for the next poll.
+  useLiveRefresh(refreshList, {
+    intervalMs: 30_000,
+    throttleMs: 1500,
+    match: (msg) =>
+      msg.type === "runs_interrupted" || laneRunChanged(msg) || sessionRunChanged(msg),
+  });
   useEffect(() => {
     const onFocus = () => refreshList();
-    const onVis = () => {
-      if (document.visibilityState === "visible") refreshList();
-    };
     window.addEventListener("focus", onFocus);
-    document.addEventListener("visibilitychange", onVis);
-    return () => {
-      window.removeEventListener("focus", onFocus);
-      document.removeEventListener("visibilitychange", onVis);
-    };
+    return () => window.removeEventListener("focus", onFocus);
   }, [refreshList]);
 
   const currentLane = selectedLaneId !== null ? lanes.find((l) => l.id === selectedLaneId) : null;