perf(ui): reduce session list churn and message block invalidation

packages/ui/src/components/instance/instance-shell2.tsx

@@ -875,7 +875,6 @@ const InstanceShell2: Component<InstanceShellProps> = (props) => {
       <div class="session-sidebar flex flex-col flex-1 min-h-0">
         <SessionList
           instanceId={props.instance.id}
-          sessions={allInstanceSessions()}
           threads={sessionThreads()}
           activeSessionId={activeSessionIdForInstance()}
           onSelect={handleSessionSelect}

packages/ui/src/components/message-block.tsx

@@ -1,4 +1,4 @@
-import { For, Match, Show, Switch, createEffect, createMemo, createSignal } from "solid-js"
+import { For, Match, Show, Switch, createEffect, createMemo, createSignal, untrack } from "solid-js"
 import { FoldVertical } from "lucide-solid"
 import MessageItem from "./message-item"
 import ToolCall from "./tool-call"
@@ -235,16 +235,11 @@ export default function MessageBlock(props: MessageBlockProps) {
     const index = props.messageIndex
     const lastAssistantIdx = props.lastAssistantIndex()
     const isQueued = current.role === "user" && (lastAssistantIdx === -1 || index > lastAssistantIdx)
-    const info = messageInfo()
-    const infoTime = (info?.time ?? {}) as { created?: number; updated?: number; completed?: number }
-    const infoTimestamp =
-      typeof infoTime.completed === "number"
-        ? infoTime.completed
-        : typeof infoTime.updated === "number"
-          ? infoTime.updated
-          : infoTime.created ?? 0
-    const infoError = (info as { error?: { name?: string } } | undefined)?.error
-    const infoErrorName = typeof infoError?.name === "string" ? infoError.name : ""
+
+    // Intentionally untracked: messageInfoVersion updates should not trigger
+    // a full message block rebuild; record revision is the invalidation key.
+    const info = untrack(messageInfo)
+
     const cacheSignature = [
       current.id,
       current.revision,
@@ -252,8 +247,6 @@ export default function MessageBlock(props: MessageBlockProps) {
       props.showThinking() ? 1 : 0,
       props.thinkingDefaultExpanded() ? 1 : 0,
       props.showUsageMetrics() ? 1 : 0,
-      infoTimestamp,
-      infoErrorName,
     ].join("|")
 
     const cachedBlock = sessionCache.messageBlocks.get(current.id)

packages/ui/src/components/session-list.tsx

@@ -1,5 +1,5 @@
 import { Component, For, Show, createSignal, createMemo, createEffect, JSX, onCleanup } from "solid-js"
-import type { Session, SessionStatus } from "../types/session"
+import type { SessionStatus } from "../types/session"
 import type { SessionThread } from "../stores/session-state"
 import { getSessionStatus } from "../stores/session-status"
 import { Bot, User, Copy, Trash2, Pencil, ShieldAlert, ChevronDown } from "lucide-solid"
@@ -14,6 +14,7 @@ import {
   isSessionParentExpanded,
   loading,
   renameSession,
+  sessions as sessionStateSessions,
   setActiveSessionFromList,
   toggleSessionParentExpanded,
 } from "../stores/sessions"
@@ -25,7 +26,6 @@ const log = getLogger("session")
 
 interface SessionListProps {
   instanceId: string
-  sessions: Map<string, Session>
   threads: SessionThread[]
   activeSessionId: string | null
   onSelect: (sessionId: string) => void
@@ -58,7 +58,7 @@ const SessionList: Component<SessionListProps> = (props) => {
  
 
   const selectSession = (sessionId: string) => {
-    const session = props.sessions.get(sessionId)
+    const session = sessionStateSessions().get(props.instanceId)?.get(sessionId)
     const parentId = session?.parentId ?? session?.id
     if (parentId) {
       ensureSessionParentExpanded(props.instanceId, parentId)
@@ -132,7 +132,7 @@ const SessionList: Component<SessionListProps> = (props) => {
   }
 
   const openRenameDialog = (sessionId: string) => {
-    const session = props.sessions.get(sessionId)
+    const session = sessionStateSessions().get(props.instanceId)?.get(sessionId)
     if (!session) return
     const label = session.title && session.title.trim() ? session.title : sessionId
     setRenameTarget({ id: sessionId, title: session.title ?? "", label })
@@ -167,7 +167,7 @@ const SessionList: Component<SessionListProps> = (props) => {
     expanded?: boolean
     onToggleExpand?: () => void
   }> = (rowProps) => {
-    const session = () => props.sessions.get(rowProps.sessionId)
+    const session = createMemo(() => sessionStateSessions().get(props.instanceId)?.get(rowProps.sessionId))
     if (!session()) {
       return <></>
     }
@@ -293,7 +293,7 @@ const SessionList: Component<SessionListProps> = (props) => {
     const activeId = props.activeSessionId
     if (!activeId || activeId === "info") return null
 
-    const activeSession = props.sessions.get(activeId)
+    const activeSession = sessionStateSessions().get(props.instanceId)?.get(activeId)
     if (!activeSession) return null
 
     return activeSession.parentId ?? activeSession.id