Optimize session status updates

Reduce per-token store churn by updating status on transitions, caching instance-level indicators, and avoiding O(n) session-map cloning.

packages/ui/src/stores/session-status.ts

@@ -1,7 +1,7 @@
 import type { Session, SessionStatus } from "../types/session"
 import type { MessageInfo } from "../types/message"
 import type { MessageRecord } from "./message-v2/types"
-import { sessions } from "./sessions"
+import { getInstanceSessionIndicatorStatusCached, sessions } from "./session-state"
 import { isSessionCompactionActive } from "./session-compaction"
 import { messageStoreBus } from "./message-v2/bus"
 
@@ -173,42 +173,7 @@ export function getSessionStatus(instanceId: string, sessionId: string): Session
 export type InstanceSessionIndicatorStatus = "permission" | SessionStatus
 
 export function getInstanceSessionIndicatorStatus(instanceId: string): InstanceSessionIndicatorStatus {
-  const instanceSessions = sessions().get(instanceId)
-  if (!instanceSessions || instanceSessions.size === 0) {
-    return "idle"
-  }
-
-  let bestRank = 0
-  let best: InstanceSessionIndicatorStatus = "idle"
-
-  for (const session of instanceSessions.values()) {
-    let rank = 0
-    let status: InstanceSessionIndicatorStatus = "idle"
-
-    if (session.pendingPermission) {
-      status = "permission"
-      rank = 3
-    } else {
-      const sessionStatus = getSessionStatus(instanceId, session.id)
-      if (sessionStatus === "compacting") {
-        status = "compacting"
-        rank = 2
-      } else if (sessionStatus === "working") {
-        status = "working"
-        rank = 1
-      }
-    }
-
-    if (rank > bestRank) {
-      bestRank = rank
-      best = status
-      if (bestRank === 3) {
-        break
-      }
-    }
-  }
-
-  return best
+  return getInstanceSessionIndicatorStatusCached(instanceId)
 }
 
 export function isSessionBusy(instanceId: string, sessionId: string): boolean {