diff --git a/src/components/conversations/conversation-detail-panel.tsx b/src/components/conversations/conversation-detail-panel.tsx
index fc50116..54aa86e 100644
--- a/src/components/conversations/conversation-detail-panel.tsx
+++ b/src/components/conversations/conversation-detail-panel.tsx
@@ -29,11 +29,7 @@ import {
   updateConversationStatus,
 } from "@/lib/tauri"
 import { useConversationRuntime } from "@/contexts/conversation-runtime-context"
-import {
-  invalidateDetailCache,
-  refreshDetailCache,
-  useDbMessageDetail,
-} from "@/hooks/use-db-message-detail"
+import { useConversationDetail } from "@/hooks/use-conversation-detail"
 import {
   extractUserImagesFromDraft,
   extractUserResourcesFromDraft,
@@ -143,17 +139,21 @@ const ConversationTabView = memo(function ConversationTabView({
   const { bindConversationTab } = useTabContext()
   const { setSessionStats } = useSessionStats()
   const {
-    acknowledgePersistedDetail,
     appendOptimisticTurn,
-    migrateConversation,
+    completeTurn,
+    refetchDetail,
+    removeConversation,
     setExternalId,
     setLiveMessage,
+    setPendingCleanup,
     setSyncState,
   } = useConversationRuntime()
 
-  const temporaryConversationId = useMemo(
-    () => buildVirtualConversationId(`draft-${tabId}`),
-    [tabId]
+  // Stable runtime session key — set once at mount, never changes.
+  // For new conversations this is a virtual (negative) ID; for existing
+  // conversations opened from the sidebar it equals the real DB ID.
+  const [effectiveConversationId] = useState(
+    () => conversationId ?? buildVirtualConversationId(`draft-${tabId}`)
   )
   const [createdConversationId, setCreatedConversationId] = useState<
     number | null
@@ -173,7 +173,11 @@ const ConversationTabView = memo(function ConversationTabView({
   const hasPersistedConversation = dbConversationId != null
   const canAutoConnect =
     hasPersistedConversation || (agentsLoaded && usableAgentCount > 0)
-  const effectiveConversationId = dbConversationId ?? temporaryConversationId
+
+  // Clear pendingCleanup when tab is (re)opened
+  useEffect(() => {
+    setPendingCleanup(effectiveConversationId, false)
+  }, [effectiveConversationId, setPendingCleanup])
 
   const latestReloadSignal = useRef(reloadSignal)
   const pendingReloadState = useRef<{
@@ -181,10 +185,10 @@ const ConversationTabView = memo(function ConversationTabView({
     sawLoading: boolean
   } | null>(null)
   const dbConvIdRef = useRef<number | null>(conversationId)
+  const mountedRef = useRef(true)
   const statusUpdatedRef = useRef(false)
   const selectedAgentRef = useRef(selectedAgent)
   const createConversationPendingRef = useRef(false)
-  const reconcileTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
   const externalIdSavedRef = useRef(false)
   const sessionIdRef = useRef<string | null>(null)
 
@@ -200,8 +204,7 @@ const ConversationTabView = memo(function ConversationTabView({
     detail,
     loading: detailLoading,
     error: detailError,
-    refetch: refetchConversationDetail,
-  } = useDbMessageDetail(effectiveConversationId)
+  } = useConversationDetail(effectiveConversationId)
 
   useEffect(() => {
     if (!isActive) return
@@ -271,56 +274,65 @@ const ConversationTabView = memo(function ConversationTabView({
     return conn.modes?.current_mode_id ?? connectionModes[0]?.id ?? null
   }, [conn.modes?.current_mode_id, connectionModes, modeId])
 
-  const clearReconcileTimer = useCallback(() => {
-    if (!reconcileTimerRef.current) return
-    clearTimeout(reconcileTimerRef.current)
-    reconcileTimerRef.current = null
-  }, [])
-
-  const refreshFromDb = useCallback(
-    async (refreshConversationId: number) => {
-      try {
-        const refreshed = await refreshDetailCache(refreshConversationId)
-        // Skip ACK during prompting to avoid clearing liveMessage /
-        // resetting syncState while streaming. The useEffect with the
-        // connStatus === "prompting" guard will handle it naturally
-        // once prompting ends.
-        if (connStatusRef.current === "prompting") return
-        acknowledgePersistedDetail(refreshConversationId, refreshed)
-      } catch (error) {
-        setSyncState(refreshConversationId, "failed")
-        console.error(
-          "[ConversationTabView] refresh detail cache failed:",
-          error
-        )
-      }
-    },
-    [acknowledgePersistedDetail, setSyncState]
-  )
-
   useEffect(() => {
     if (connSessionId) {
       sessionIdRef.current = connSessionId
     }
   }, [connSessionId])
 
+  // completeTurn MUST be declared BEFORE setLiveMessage so that React runs
+  // its cleanup/setup before setLiveMessage's cleanup. When connStatus
+  // transitions away from "prompting", completeTurn snapshots and promotes
+  // the liveMessage first, then setLiveMessage's cleanup safely clears it.
+  const prevConnStatusRef = useRef(connStatus)
   useEffect(() => {
-    setLiveMessage(effectiveConversationId, conn.liveMessage ?? null)
+    const wasPrompting = prevConnStatusRef.current === "prompting"
+    prevConnStatusRef.current = connStatus
+    if (!wasPrompting || connStatus === "prompting") return
+
+    // Turn completed — promote liveMessage + optimisticTurns to localTurns
+    completeTurn(effectiveConversationId)
+
+    const persistedId = dbConvIdRef.current
+    if (!persistedId) return
+
+    if (connStatus !== "disconnected" && connStatus !== "error") {
+      updateConversationStatus(persistedId, "pending_review")
+        .then(() => refreshConversations())
+        .catch((e: unknown) =>
+          console.error("[ConversationTabView] update status:", e)
+        )
+    }
+  }, [completeTurn, connStatus, effectiveConversationId, refreshConversations])
+
+  useEffect(() => {
+    // Only sync non-null liveMessage updates to state. When conn.liveMessage
+    // goes null (agent finished streaming), don't clear state.liveMessage —
+    // COMPLETE_TURN needs to snapshot it when connStatus transitions.
+    // Clearing is handled by COMPLETE_TURN (sets liveMessage = null) and
+    // by this effect's cleanup (when not prompting).
+    if (conn.liveMessage != null) {
+      setLiveMessage(effectiveConversationId, conn.liveMessage)
+    }
     return () => {
-      setLiveMessage(effectiveConversationId, null)
+      // Don't clear liveMessage if agent is still responding — the session
+      // is kept via pendingCleanup, and clearing here would cause the
+      // SET_LIVE_MESSAGE guard to block the reconnect liveMessage on reopen.
+      if (connStatusRef.current !== "prompting") {
+        setLiveMessage(effectiveConversationId, null)
+      }
     }
   }, [conn.liveMessage, effectiveConversationId, setLiveMessage])
 
   useEffect(() => {
-    if (!dbConversationId) return
-    setExternalId(dbConversationId, detail?.summary.external_id ?? null)
-  }, [dbConversationId, detail?.summary.external_id, setExternalId])
+    if (effectiveConversationId <= 0) return
+    setExternalId(effectiveConversationId, detail?.summary.external_id ?? null)
+  }, [effectiveConversationId, detail?.summary.external_id, setExternalId])
 
   useEffect(() => {
-    if (!dbConversationId) return
     if (!connSessionId) return
-    setExternalId(dbConversationId, connSessionId)
-  }, [connSessionId, dbConversationId, setExternalId])
+    setExternalId(effectiveConversationId, connSessionId)
+  }, [connSessionId, effectiveConversationId, setExternalId])
 
   const trySaveExternalId = useCallback(() => {
     if (
@@ -345,45 +357,6 @@ const ConversationTabView = memo(function ConversationTabView({
     }
   }, [connSessionId, trySaveExternalId])
 
-  useEffect(() => {
-    if (!dbConversationId) return
-    if (!detail) return
-    if (connStatus === "prompting") return
-    acknowledgePersistedDetail(dbConversationId, detail)
-  }, [acknowledgePersistedDetail, connStatus, dbConversationId, detail])
-
-  const prevConnStatusRef = useRef(connStatus)
-  useEffect(() => {
-    const wasPrompting = prevConnStatusRef.current === "prompting"
-    prevConnStatusRef.current = connStatus
-    if (!wasPrompting || connStatus === "prompting") return
-
-    setSyncState(effectiveConversationId, "reconciling")
-    const persistedId = dbConvIdRef.current
-    if (!persistedId) return
-
-    invalidateDetailCache(persistedId)
-    clearReconcileTimer()
-    reconcileTimerRef.current = setTimeout(() => {
-      void refreshFromDb(persistedId)
-    }, 1200)
-
-    if (connStatus !== "disconnected" && connStatus !== "error") {
-      updateConversationStatus(persistedId, "pending_review")
-        .then(() => refreshConversations())
-        .catch((e: unknown) =>
-          console.error("[ConversationTabView] update status:", e)
-        )
-    }
-  }, [
-    clearReconcileTimer,
-    connStatus,
-    effectiveConversationId,
-    refreshConversations,
-    refreshFromDb,
-    setSyncState,
-  ])
-
   useEffect(() => {
     if (connStatus === "connected" || connStatus === "prompting") {
       statusUpdatedRef.current = false
@@ -413,8 +386,8 @@ const ConversationTabView = memo(function ConversationTabView({
       signal: reloadSignal,
       sawLoading: false,
     }
-    refetchConversationDetail()
-  }, [dbConversationId, reloadSignal, refetchConversationDetail])
+    refetchDetail(dbConversationId)
+  }, [dbConversationId, reloadSignal, refetchDetail])
 
   useEffect(() => {
     const pending = pendingReloadState.current
@@ -437,7 +410,19 @@ const ConversationTabView = memo(function ConversationTabView({
     toast.success(t("reloaded"))
   }, [detailLoading, detailError, t])
 
-  useEffect(() => clearReconcileTimer, [clearReconcileTimer])
+  // Cleanup runtime data on unmount (tab close)
+  useEffect(() => {
+    mountedRef.current = true
+    return () => {
+      mountedRef.current = false
+      if (connStatusRef.current === "prompting") {
+        // Agent still responding — mark for deferred cleanup
+        setPendingCleanup(effectiveConversationId, true)
+      } else {
+        removeConversation(effectiveConversationId)
+      }
+    }
+  }, [effectiveConversationId, removeConversation, setPendingCleanup])
 
   const handleSend = useCallback(
     (draft: PromptDraft, selectedModeIdArg?: string | null) => {
@@ -481,22 +466,31 @@ const ConversationTabView = memo(function ConversationTabView({
       createConversation(folderId, selectedAgent, title)
         .then((newConversationId) => {
           dbConvIdRef.current = newConversationId
+          // Set external ID on the stable virtual session (no migration needed —
+          // effectiveConversationId never changes, so the session stays in place)
+          setExternalId(effectiveConversationId, sessionIdRef.current ?? null)
+          trySaveExternalId()
+
+          if (!mountedRef.current) {
+            // Component unmounted while creating — mark for deferred cleanup
+            // so the background turn_complete handler can clean up later.
+            setPendingCleanup(effectiveConversationId, true)
+            refreshConversations()
+            return
+          }
+
           setCreatedConversationId(newConversationId)
-          migrateConversation(temporaryConversationId, newConversationId)
-          setExternalId(newConversationId, sessionIdRef.current ?? null)
           bindConversationTab(tabId, newConversationId, selectedAgent, title)
           moveMessageInputDraft(
             buildNewConversationDraftStorageKey({ folderId }),
             buildConversationDraftStorageKey(selectedAgent, newConversationId)
           )
-          trySaveExternalId()
           statusUpdatedRef.current = false
           updateConversationStatus(newConversationId, "in_progress")
             .then(() => refreshConversations())
             .catch((e: unknown) =>
               console.error("[ConversationTabView] update status:", e)
             )
-          void refreshFromDb(newConversationId)
         })
         .catch((e: unknown) =>
           console.error("[ConversationTabView] create conversation:", e)
@@ -514,16 +508,13 @@ const ConversationTabView = memo(function ConversationTabView({
       folderId,
       hasPersistedConversation,
       lifecycleSend,
-      migrateConversation,
       refreshConversations,
-      refreshFromDb,
       selectedAgent,
       setExternalId,
       setSyncState,
       sharedT,
       tWelcome,
       tabId,
-      temporaryConversationId,
       trySaveExternalId,
     ]
   )
@@ -598,8 +589,8 @@ const ConversationTabView = memo(function ConversationTabView({
     ]
   )
 
-  const showDraftHeader = !hasPersistedConversation
-  const isWelcomeMode = showDraftHeader && !hasSentMessage
+  const showDraftHeader = !hasPersistedConversation && !hasSentMessage
+  const isWelcomeMode = showDraftHeader
 
   const messageListNode = (
     <MessageListView
@@ -611,7 +602,7 @@ const ConversationTabView = memo(function ConversationTabView({
       sessionStats={detail?.session_stats ?? null}
       detailLoading={detailLoading}
       detailError={detailError}
-      hideEmptyState={showDraftHeader}
+      hideEmptyState={!hasPersistedConversation || hasSentMessage}
     />
   )
 
@@ -735,9 +726,10 @@ const ConversationTabView = memo(function ConversationTabView({
 export function ConversationDetailPanel() {
   const t = useTranslations("Folder.conversation")
   const {
-    acknowledgePersistedDetail,
+    completeTurn: runtimeCompleteTurn,
     getConversationIdByExternalId,
-    setSyncState,
+    getSession,
+    removeConversation: runtimeRemoveConversation,
   } = useConversationRuntime()
   const { folder, newConversation, conversations, refreshConversations } =
     useFolderContext()
@@ -752,10 +744,6 @@ export function ConversationDetailPanel() {
   const [reloadByTabId, setReloadByTabId] = useState<Record<string, number>>({})
   const tabsRef = useRef(tabs)
   const conversationsRef = useRef(conversations)
-  const pendingClosedConversationIdsRef = useRef<Set<number>>(new Set())
-  const pendingRefreshTimerRef = useRef<ReturnType<typeof setTimeout> | null>(
-    null
-  )
 
   useEffect(() => {
     tabsRef.current = tabs
@@ -765,64 +753,10 @@ export function ConversationDetailPanel() {
     conversationsRef.current = conversations
   }, [conversations])
 
-  const flushClosedConversationRefresh = useCallback(() => {
-    const conversationIds = Array.from(pendingClosedConversationIdsRef.current)
-    if (conversationIds.length === 0) return
-    pendingClosedConversationIdsRef.current.clear()
-
-    void (async () => {
-      await Promise.all(
-        conversationIds.map(async (conversationId) => {
-          const summary =
-            conversationsRef.current.find(
-              (item) => item.id === conversationId
-            ) ?? null
-          if (summary?.status === "in_progress") {
-            try {
-              await updateConversationStatus(conversationId, "pending_review")
-            } catch (error) {
-              console.error(
-                "[ConversationDetailPanel] background update status failed:",
-                error
-              )
-            }
-          }
-
-          try {
-            const detail = await refreshDetailCache(conversationId)
-            acknowledgePersistedDetail(conversationId, detail)
-          } catch (error) {
-            setSyncState(conversationId, "failed")
-            console.error(
-              "[ConversationDetailPanel] background detail cache refresh failed:",
-              error
-            )
-          }
-        })
-      )
-
-      refreshConversations()
-    })()
-  }, [acknowledgePersistedDetail, refreshConversations, setSyncState])
-
-  const scheduleClosedConversationRefresh = useCallback(
-    (conversationId: number) => {
-      pendingClosedConversationIdsRef.current.add(conversationId)
-      if (pendingRefreshTimerRef.current) return
-
-      // Delay briefly so local session file writes can settle.
-      pendingRefreshTimerRef.current = setTimeout(() => {
-        pendingRefreshTimerRef.current = null
-        flushClosedConversationRefresh()
-      }, 1200)
-    },
-    [flushClosedConversationRefresh]
-  )
-
+  // Background turn_complete handler: for conversations not open in tabs
   useEffect(() => {
     let cancelled = false
     let unlisten: (() => void | Promise<void>) | null = null
-    const pendingClosedConversationIds = pendingClosedConversationIdsRef.current
 
     void import("@tauri-apps/api/event")
       .then(({ listen }) =>
@@ -840,15 +774,40 @@ export function ConversationDetailPanel() {
             runtimeConversationId ?? summary?.id ?? null
           if (!matchedConversationId) return
 
+          // Check both virtual (runtime) ID and real DB ID — after
+          // bindConversationTab the tab stores the real DB ID while the
+          // runtime session may still be keyed by the virtual ID.
+          const dbId2 = summary?.id
           const isOpenInTabs = tabsRef.current.some(
-            (tab) => tab.conversationId === matchedConversationId
+            (tab) =>
+              tab.conversationId === matchedConversationId ||
+              (dbId2 != null && tab.conversationId === dbId2)
           )
           if (isOpenInTabs) return
 
-          invalidateDetailCache(matchedConversationId)
-          setSyncState(matchedConversationId, "reconciling")
+          // Promote liveMessage + optimisticTurns to localTurns immediately
+          runtimeCompleteTurn(matchedConversationId)
 
-          scheduleClosedConversationRefresh(matchedConversationId)
+          // If tab was closed while agent was responding, clean up now
+          const session = getSession(matchedConversationId)
+          if (session?.pendingCleanup) {
+            runtimeRemoveConversation(matchedConversationId)
+          }
+
+          // Update conversation status — use the DB summary (found by
+          // external_id above) since matchedConversationId may be a virtual
+          // (negative) ID that won't match any DB record.
+          const dbId = summary?.id ?? (matchedConversationId > 0 ? matchedConversationId : null)
+          if (dbId && (!summary || summary.status === "in_progress")) {
+            updateConversationStatus(dbId, "pending_review")
+              .then(() => refreshConversations())
+              .catch((error: unknown) =>
+                console.error(
+                  "[ConversationDetailPanel] background update status:",
+                  error
+                )
+              )
+          }
         })
       )
       .then((dispose) => {
@@ -867,11 +826,6 @@ export function ConversationDetailPanel() {
 
     return () => {
       cancelled = true
-      if (pendingRefreshTimerRef.current) {
-        clearTimeout(pendingRefreshTimerRef.current)
-        pendingRefreshTimerRef.current = null
-      }
-      pendingClosedConversationIds.clear()
       disposeTauriListener(
         unlisten,
         "ConversationDetailPanel.backgroundRefresh"
@@ -879,9 +833,10 @@ export function ConversationDetailPanel() {
     }
   }, [
     getConversationIdByExternalId,
-    acknowledgePersistedDetail,
-    scheduleClosedConversationRefresh,
-    setSyncState,
+    getSession,
+    runtimeCompleteTurn,
+    runtimeRemoveConversation,
+    refreshConversations,
   ])
 
   const hasNoTabs = tabs.length === 0 && !activeTabId
diff --git a/src/components/layout/aux-panel-session-files-tab.tsx b/src/components/layout/aux-panel-session-files-tab.tsx
index 7b9c1ee..1515faf 100644
--- a/src/components/layout/aux-panel-session-files-tab.tsx
+++ b/src/components/layout/aux-panel-session-files-tab.tsx
@@ -7,7 +7,7 @@ import { useFolderContext } from "@/contexts/folder-context"
 import { useTabContext } from "@/contexts/tab-context"
 import { useConversationRuntime } from "@/contexts/conversation-runtime-context"
 import { useWorkspaceContext } from "@/contexts/workspace-context"
-import { useDbMessageDetail } from "@/hooks/use-db-message-detail"
+import { useConversationDetail } from "@/hooks/use-conversation-detail"
 import { extractSessionFilesGrouped } from "@/lib/session-files"
 import {
   CommitFileAdditions,
@@ -54,7 +54,7 @@ function toFolderRelativePath(filePath: string, folderPath?: string): string {
 
 function SessionFilesContent({ conversationId }: { conversationId: number }) {
   const t = useTranslations("Folder.sessionFiles")
-  const { loading } = useDbMessageDetail(conversationId)
+  const { loading } = useConversationDetail(conversationId)
   const { getTimelineTurns } = useConversationRuntime()
   const { openSessionFileDiff } = useWorkspaceContext()
   const { folder } = useFolderContext()
diff --git a/src/components/message/message-list-view.tsx b/src/components/message/message-list-view.tsx
index 6ecf13d..5103d9b 100644
--- a/src/components/message/message-list-view.tsx
+++ b/src/components/message/message-list-view.tsx
@@ -5,10 +5,9 @@ import { useConversationRuntime } from "@/contexts/conversation-runtime-context"
 import { ContentPartsRenderer } from "./content-parts-renderer"
 import {
   adaptMessageTurns,
-  type MessageGroup,
+  type AdaptedContentPart,
   type UserImageDisplay,
   type UserResourceDisplay,
-  groupAdaptedMessages,
 } from "@/lib/adapters/ai-elements-adapter"
 import { TurnStats } from "./turn-stats"
 import { LiveTurnStats } from "./live-turn-stats"
@@ -40,9 +39,16 @@ interface MessageListViewProps {
   hideEmptyState?: boolean
 }
 
-interface ResolvedMessageGroup extends MessageGroup {
+interface ResolvedMessageGroup {
+  id: string
+  role: "user" | "assistant" | "system"
+  parts: AdaptedContentPart[]
   resources: UserResourceDisplay[]
   images: UserImageDisplay[]
+  usage?: import("@/lib/types").TurnUsage | null
+  duration_ms?: number | null
+  model?: string | null
+  models?: string[]
 }
 
 type ThreadRenderItem =
@@ -186,36 +192,27 @@ export function MessageListView({
       (_, index) => timelineTurns[index].phase !== "streaming"
     )
 
-    // Group adapted messages per phase-chunk to prevent merging
-    // assistant turns across phase boundaries (e.g. persisted + streaming).
-    const items: ThreadRenderItem[] = []
-    let chunkStart = 0
-    while (chunkStart < allAdapted.length) {
-      const chunkPhase = timelineTurns[chunkStart].phase
-      let chunkEnd = chunkStart + 1
-      while (
-        chunkEnd < allAdapted.length &&
-        timelineTurns[chunkEnd].phase === chunkPhase
-      ) {
-        chunkEnd++
+    // Map each adapted message directly to a render item (1:1).
+    // Backend group_into_turns() already ensures each turn is a complete unit.
+    const items: ThreadRenderItem[] = allAdapted.map((msg, i) => {
+      const phase = timelineTurns[i].phase
+      const role = msg.role === "tool" ? "assistant" : msg.role
+      return {
+        key: `${phase}-${msg.id}-${i}`,
+        kind: "turn" as const,
+        group: {
+          id: msg.id,
+          role,
+          parts: msg.content,
+          resources: msg.userResources ?? [],
+          images: msg.userImages ?? [],
+          usage: msg.usage,
+          duration_ms: msg.duration_ms,
+          model: msg.model,
+        },
+        phase,
       }
-      const chunkAdapted = allAdapted.slice(chunkStart, chunkEnd)
-      const groups = groupAdaptedMessages(chunkAdapted)
-      for (let i = 0; i < groups.length; i++) {
-        const group = groups[i]
-        items.push({
-          key: `${chunkPhase}-${chunkStart}-${group.id}-${i}`,
-          kind: "turn",
-          group: {
-            ...group,
-            resources: group.userResources ?? [],
-            images: group.userImages ?? [],
-          },
-          phase: chunkPhase,
-        })
-      }
-      chunkStart = chunkEnd
-    }
+    })
 
     const lastPhase = timelineTurns[timelineTurns.length - 1]?.phase ?? null
     if (
diff --git a/src/contexts/conversation-runtime-context.tsx b/src/contexts/conversation-runtime-context.tsx
index 61aaff4..274a0c5 100644
--- a/src/contexts/conversation-runtime-context.tsx
+++ b/src/contexts/conversation-runtime-context.tsx
@@ -6,17 +6,15 @@ import {
   useContext,
   useMemo,
   useReducer,
+  useRef,
   type ReactNode,
 } from "react"
 import type { LiveMessage } from "@/contexts/acp-connections-context"
+import { getFolderConversation } from "@/lib/tauri"
 import type { DbConversationDetail, MessageTurn } from "@/lib/types"
 import { inferLiveToolName } from "@/lib/tool-call-normalization"
 
-export type ConversationSyncState =
-  | "idle"
-  | "awaiting_persist"
-  | "reconciling"
-  | "failed"
+export type ConversationSyncState = "idle" | "awaiting_persist"
 
 export type ConversationTimelinePhase = "persisted" | "optimistic" | "streaming"
 
@@ -29,15 +27,25 @@ export interface ConversationTimelineTurn {
 export interface ConversationRuntimeSession {
   conversationId: number
   externalId: string | null
-  persistedTurns: MessageTurn[]
+
+  // DB data (cold open only)
+  detail: DbConversationDetail | null
+  detailLoading: boolean
+  detailError: string | null
+
+  // Active session accumulated turns (promoted optimistic + completed streaming)
+  localTurns: MessageTurn[]
+
+  // Temporary state
   optimisticTurns: MessageTurn[]
   liveMessage: LiveMessage | null
+
+  // Sync
   syncState: ConversationSyncState
   activeTurnToken: string | null
-  lastHydratedAt: number | null
-  lastPersistedAt: number | null
-  persistedUpdatedAt: string | null
-  persistedMessageCount: number
+
+  // Cleanup
+  pendingCleanup: boolean
 }
 
 interface ConversationRuntimeState {
@@ -51,7 +59,24 @@ const initialState: ConversationRuntimeState = {
 }
 
 type Action =
-  | { type: "HYDRATE_FROM_DETAIL"; detail: DbConversationDetail }
+  | {
+      type: "FETCH_DETAIL_START"
+      conversationId: number
+    }
+  | {
+      type: "FETCH_DETAIL_SUCCESS"
+      conversationId: number
+      detail: DbConversationDetail
+    }
+  | {
+      type: "FETCH_DETAIL_ERROR"
+      conversationId: number
+      error: string
+    }
+  | {
+      type: "COMPLETE_TURN"
+      conversationId: number
+    }
   | {
       type: "APPEND_OPTIMISTIC_TURN"
       conversationId: number
@@ -63,12 +88,6 @@ type Action =
       conversationId: number
       liveMessage: LiveMessage | null
     }
-  | {
-      type: "ACK_PERSISTED_DETAIL"
-      conversationId: number
-      detail: DbConversationDetail
-      turnToken?: string | null
-    }
   | {
       type: "SET_EXTERNAL_ID"
       conversationId: number
@@ -84,6 +103,11 @@ type Action =
       fromConversationId: number
       toConversationId: number
     }
+  | {
+      type: "SET_PENDING_CLEANUP"
+      conversationId: number
+      pendingCleanup: boolean
+    }
   | { type: "REMOVE_CONVERSATION"; conversationId: number }
   | { type: "RESET" }
 
@@ -93,15 +117,15 @@ function createEmptySession(
   return {
     conversationId,
     externalId: null,
-    persistedTurns: [],
+    detail: null,
+    detailLoading: false,
+    detailError: null,
+    localTurns: [],
     optimisticTurns: [],
     liveMessage: null,
     syncState: "idle",
     activeTurnToken: null,
-    lastHydratedAt: null,
-    lastPersistedAt: null,
-    persistedUpdatedAt: null,
-    persistedMessageCount: 0,
+    pendingCleanup: false,
   }
 }
 
@@ -179,24 +203,6 @@ function buildStreamingTurnFromLiveMessage(
   }
 }
 
-function shouldAcceptPersistedSnapshot(
-  current: ConversationRuntimeSession | undefined,
-  detail: DbConversationDetail
-): boolean {
-  if (!current) return true
-
-  const nextUpdatedAt = detail.summary.updated_at ?? null
-  const nextMessageCount = detail.summary.message_count
-  const nextTurnCount = detail.turns.length
-
-  if (nextMessageCount < current.persistedMessageCount) return false
-  if (nextTurnCount < current.persistedTurns.length) return false
-  if (!current.persistedUpdatedAt || !nextUpdatedAt) return true
-  if (nextUpdatedAt < current.persistedUpdatedAt) return false
-
-  return true
-}
-
 function upsertExternalIdIndex(
   index: Map<string, number>,
   previousExternalId: string | null,
@@ -213,74 +219,18 @@ function upsertExternalIdIndex(
   return next
 }
 
-function reduceHydrateDetail(
+function updateSessionInState(
   state: ConversationRuntimeState,
   conversationId: number,
-  detail: DbConversationDetail
+  updater: (current: ConversationRuntimeSession) => ConversationRuntimeSession
 ): ConversationRuntimeState {
-  const current = state.byConversationId.get(conversationId)
-  const nextExternalId = detail.summary.external_id ?? null
-  const acceptSnapshot = shouldAcceptPersistedSnapshot(current, detail)
-  const prevPersistedTurnCount = current?.persistedTurns.length ?? 0
-  const prevPersistedMessageCount = current?.persistedMessageCount ?? 0
-  const optimisticTurns = current?.optimisticTurns ?? []
-  const persistedTurns = acceptSnapshot
-    ? detail.turns
-    : (current?.persistedTurns ?? [])
-  const nextPersistedUpdatedAt = acceptSnapshot
-    ? (detail.summary.updated_at ?? null)
-    : (current?.persistedUpdatedAt ?? null)
-  const nextPersistedMessageCount = acceptSnapshot
-    ? detail.summary.message_count
-    : (current?.persistedMessageCount ?? 0)
-  const shouldDropOptimistic =
-    optimisticTurns.length > 0 &&
-    persistedTurns.length >= (current?.persistedTurns.length ?? 0) + 1
-  // Content advance: actual turns or messages grew — safe to clear
-  // liveMessage because persisted data now covers the streamed content.
-  const hasContentAdvance =
-    acceptSnapshot &&
-    (detail.turns.length > prevPersistedTurnCount ||
-      detail.summary.message_count > prevPersistedMessageCount)
-  // Note: updated_at changes (e.g. status update bumping the timestamp)
-  // are NOT treated as content advance. Only actual turns / message_count
-  // growth should clear liveMessage, because a metadata-only bump could
-  // arrive before the session file is flushed to disk.
-
-  const nextSession: ConversationRuntimeSession = {
-    ...(current ?? createEmptySession(conversationId)),
-    externalId: nextExternalId,
-    persistedTurns,
-    liveMessage:
-      hasContentAdvance && current?.syncState !== "awaiting_persist"
-        ? null
-        : (current?.liveMessage ?? null),
-    optimisticTurns: shouldDropOptimistic ? [] : optimisticTurns,
-    syncState: shouldDropOptimistic ? "idle" : (current?.syncState ?? "idle"),
-    activeTurnToken: shouldDropOptimistic
-      ? null
-      : (current?.activeTurnToken ?? null),
-    lastHydratedAt: Date.now(),
-    lastPersistedAt: acceptSnapshot
-      ? Date.now()
-      : (current?.lastPersistedAt ?? null),
-    persistedUpdatedAt: nextPersistedUpdatedAt,
-    persistedMessageCount: nextPersistedMessageCount,
-  }
-
+  const current =
+    state.byConversationId.get(conversationId) ??
+    createEmptySession(conversationId)
+  const nextSession = updater(current)
   const nextByConversationId = new Map(state.byConversationId)
   nextByConversationId.set(conversationId, nextSession)
-  const nextExternalIndex = upsertExternalIdIndex(
-    state.conversationIdByExternalId,
-    current?.externalId ?? null,
-    nextExternalId,
-    conversationId
-  )
-
-  return {
-    byConversationId: nextByConversationId,
-    conversationIdByExternalId: nextExternalIndex,
-  }
+  return { ...state, byConversationId: nextByConversationId }
 }
 
 function reducer(
@@ -288,73 +238,125 @@ function reducer(
   action: Action
 ): ConversationRuntimeState {
   switch (action.type) {
-    case "HYDRATE_FROM_DETAIL":
-      return reduceHydrateDetail(state, action.detail.summary.id, action.detail)
+    case "FETCH_DETAIL_START":
+      return updateSessionInState(state, action.conversationId, (current) => ({
+        ...current,
+        detailLoading: true,
+        detailError: null,
+      }))
 
-    case "APPEND_OPTIMISTIC_TURN": {
+    case "FETCH_DETAIL_SUCCESS": {
       const current =
         state.byConversationId.get(action.conversationId) ??
         createEmptySession(action.conversationId)
+      const nextExternalId = action.detail.summary.external_id ?? null
+
+      // DB data is authoritative for completed turns — always clear localTurns.
+      // Only preserve optimisticTurns + liveMessage if user actively sent
+      // a message and is awaiting agent response.
+      const isActivelyInteracting =
+        current.syncState === "awaiting_persist"
+
       const nextSession: ConversationRuntimeSession = {
+        ...current,
+        detail: action.detail,
+        detailLoading: false,
+        detailError: null,
+        externalId: nextExternalId ?? current.externalId,
+        localTurns: [],
+        ...(isActivelyInteracting
+          ? {}
+          : { optimisticTurns: [], liveMessage: null }),
+      }
+
+      const nextByConversationId = new Map(state.byConversationId)
+      nextByConversationId.set(action.conversationId, nextSession)
+      const nextExternalIndex = upsertExternalIdIndex(
+        state.conversationIdByExternalId,
+        current.externalId,
+        nextExternalId ?? current.externalId,
+        action.conversationId
+      )
+
+      return {
+        byConversationId: nextByConversationId,
+        conversationIdByExternalId: nextExternalIndex,
+      }
+    }
+
+    case "FETCH_DETAIL_ERROR":
+      return updateSessionInState(state, action.conversationId, (current) => ({
+        ...current,
+        detailLoading: false,
+        detailError: action.error,
+      }))
+
+    case "COMPLETE_TURN": {
+      const current = state.byConversationId.get(action.conversationId)
+      if (!current) return state
+
+      // Convert liveMessage to a completed MessageTurn
+      const streamingTurn = current.liveMessage
+        ? buildStreamingTurnFromLiveMessage(
+            current.conversationId,
+            current.liveMessage
+          )
+        : null
+
+      // Promote: optimisticTurns + streamingTurn → localTurns
+      const promoted = [...current.localTurns, ...current.optimisticTurns]
+      if (streamingTurn) promoted.push(streamingTurn)
+
+      return updateSessionInState(state, action.conversationId, () => ({
+        ...current,
+        localTurns: promoted,
+        optimisticTurns: [],
+        liveMessage: null,
+        syncState: "idle",
+        activeTurnToken: null,
+      }))
+    }
+
+    case "APPEND_OPTIMISTIC_TURN":
+      return updateSessionInState(state, action.conversationId, (current) => ({
         ...current,
         optimisticTurns: [...current.optimisticTurns, action.turn],
         syncState: "awaiting_persist",
         activeTurnToken: action.turnToken,
-      }
-      const nextByConversationId = new Map(state.byConversationId)
-      nextByConversationId.set(action.conversationId, nextSession)
-      return { ...state, byConversationId: nextByConversationId }
-    }
+      }))
 
     case "SET_LIVE_MESSAGE": {
-      const current =
-        state.byConversationId.get(action.conversationId) ??
-        createEmptySession(action.conversationId)
+      const current = state.byConversationId.get(action.conversationId)
+
+      // Avoid creating a ghost session when clearing liveMessage on a deleted session
+      if (!current && action.liveMessage === null) return state
+
+      const session = current ?? createEmptySession(action.conversationId)
 
       // Guard: prevent stale liveMessage from ACP reconnects overriding
       // persisted data. When a session has no active liveMessage and no
-      // pending interaction (idle or reconciling without a live turn),
-      // a SET_LIVE_MESSAGE from a reconnected ACP connection carries
-      // the completed response that is already in persistedTurns.
+      // pending interaction (idle without a live turn), a SET_LIVE_MESSAGE
+      // from a reconnected ACP connection carries the completed response
+      // that is already in localTurns/detail.turns.
       // Accepting it would cause duplicate assistant text in the timeline.
+      // Also block during cold loading (detailLoading) — the reconnect
+      // liveMessage arrives before DB data, causing overlap after fetch.
+      const hasExistingTurns =
+        (session.detail?.turns.length ?? 0) > 0 ||
+        session.localTurns.length > 0
       if (
         action.liveMessage !== null &&
-        current.liveMessage === null &&
-        current.syncState !== "awaiting_persist" &&
-        current.persistedTurns.length > 0
+        session.liveMessage === null &&
+        session.syncState !== "awaiting_persist" &&
+        (hasExistingTurns || session.detailLoading)
       ) {
         return state
       }
 
-      const nextSession: ConversationRuntimeSession = {
-        ...current,
-        liveMessage: action.liveMessage,
-      }
-      const nextByConversationId = new Map(state.byConversationId)
-      nextByConversationId.set(action.conversationId, nextSession)
-      return { ...state, byConversationId: nextByConversationId }
-    }
-
-    case "ACK_PERSISTED_DETAIL": {
-      const nextState = reduceHydrateDetail(
-        state,
-        action.conversationId,
-        action.detail
-      )
-      const session = nextState.byConversationId.get(action.conversationId)
-      if (!session) return nextState
-      const nextSession: ConversationRuntimeSession = {
+      return updateSessionInState(state, action.conversationId, () => ({
         ...session,
-        syncState: "idle",
-        activeTurnToken:
-          action.turnToken != null &&
-          action.turnToken === session.activeTurnToken
-            ? null
-            : session.activeTurnToken,
-      }
-      const nextByConversationId = new Map(nextState.byConversationId)
-      nextByConversationId.set(action.conversationId, nextSession)
-      return { ...nextState, byConversationId: nextByConversationId }
+        liveMessage: action.liveMessage,
+      }))
     }
 
     case "SET_EXTERNAL_ID": {
@@ -379,18 +381,11 @@ function reducer(
       }
     }
 
-    case "SET_SYNC_STATE": {
-      const current =
-        state.byConversationId.get(action.conversationId) ??
-        createEmptySession(action.conversationId)
-      const nextSession: ConversationRuntimeSession = {
+    case "SET_SYNC_STATE":
+      return updateSessionInState(state, action.conversationId, (current) => ({
         ...current,
         syncState: action.syncState,
-      }
-      const nextByConversationId = new Map(state.byConversationId)
-      nextByConversationId.set(action.conversationId, nextSession)
-      return { ...state, byConversationId: nextByConversationId }
-    }
+      }))
 
     case "MIGRATE_CONVERSATION": {
       if (action.fromConversationId === action.toConversationId) return state
@@ -400,33 +395,20 @@ function reducer(
         state.byConversationId.get(action.toConversationId) ??
         createEmptySession(action.toConversationId)
 
-      const preferFromSnapshot =
-        from.persistedTurns.length >= to.persistedTurns.length
       const mergedLiveMessage = to.liveMessage ?? from.liveMessage
 
       const merged: ConversationRuntimeSession = {
         ...to,
         ...from,
         conversationId: action.toConversationId,
-        persistedTurns: preferFromSnapshot
-          ? from.persistedTurns
-          : to.persistedTurns,
+        detail: to.detail ?? from.detail,
+        detailLoading: to.detailLoading || from.detailLoading,
+        detailError: to.detailError ?? from.detailError,
+        localTurns: [...from.localTurns, ...to.localTurns],
         optimisticTurns: [...from.optimisticTurns, ...to.optimisticTurns],
         liveMessage: mergedLiveMessage,
         syncState: to.syncState !== "idle" ? to.syncState : from.syncState,
         activeTurnToken: to.activeTurnToken ?? from.activeTurnToken,
-        lastHydratedAt:
-          Math.max(from.lastHydratedAt ?? 0, to.lastHydratedAt ?? 0) || null,
-        lastPersistedAt:
-          Math.max(from.lastPersistedAt ?? 0, to.lastPersistedAt ?? 0) || null,
-        persistedUpdatedAt:
-          (to.persistedUpdatedAt ?? "") > (from.persistedUpdatedAt ?? "")
-            ? to.persistedUpdatedAt
-            : from.persistedUpdatedAt,
-        persistedMessageCount: Math.max(
-          from.persistedMessageCount,
-          to.persistedMessageCount
-        ),
       }
 
       const nextByConversationId = new Map(state.byConversationId)
@@ -449,6 +431,12 @@ function reducer(
       }
     }
 
+    case "SET_PENDING_CLEANUP":
+      return updateSessionInState(state, action.conversationId, (current) => ({
+        ...current,
+        pendingCleanup: action.pendingCleanup,
+      }))
+
     case "REMOVE_CONVERSATION": {
       const current = state.byConversationId.get(action.conversationId)
       if (!current) return state
@@ -473,7 +461,9 @@ interface ConversationRuntimeContextValue {
   getSession: (conversationId: number) => ConversationRuntimeSession | null
   getConversationIdByExternalId: (externalId: string) => number | null
   getTimelineTurns: (conversationId: number) => ConversationTimelineTurn[]
-  hydrateFromDetail: (detail: DbConversationDetail) => void
+  fetchDetail: (conversationId: number) => void
+  refetchDetail: (conversationId: number) => void
+  completeTurn: (conversationId: number) => void
   appendOptimisticTurn: (
     conversationId: number,
     turn: MessageTurn,
@@ -483,11 +473,6 @@ interface ConversationRuntimeContextValue {
     conversationId: number,
     liveMessage: LiveMessage | null
   ) => void
-  acknowledgePersistedDetail: (
-    conversationId: number,
-    detail: DbConversationDetail,
-    turnToken?: string | null
-  ) => void
   setExternalId: (conversationId: number, externalId: string | null) => void
   setSyncState: (
     conversationId: number,
@@ -497,6 +482,7 @@ interface ConversationRuntimeContextValue {
     fromConversationId: number,
     toConversationId: number
   ) => void
+  setPendingCleanup: (conversationId: number, pendingCleanup: boolean) => void
   removeConversation: (conversationId: number) => void
   reset: () => void
 }
@@ -511,6 +497,9 @@ export function ConversationRuntimeProvider({
 }) {
   const [state, dispatch] = useReducer(reducer, initialState)
 
+  const stateRef = useRef(state)
+  stateRef.current = state
+
   const getSession = useCallback(
     (conversationId: number) =>
       state.byConversationId.get(conversationId) ?? null,
@@ -528,43 +517,98 @@ export function ConversationRuntimeProvider({
       const session = state.byConversationId.get(conversationId)
       if (!session) return []
 
-      const persisted: ConversationTimelineTurn[] = session.persistedTurns.map(
+      // Phase 1: DB historical turns
+      const persisted: ConversationTimelineTurn[] = (
+        session.detail?.turns ?? []
+      ).map((turn, index) => ({
+        key: `persisted-${conversationId}-${turn.id}-${index}`,
+        turn,
+        phase: "persisted",
+      }))
+
+      // Phase 2: Locally completed turns (promoted optimistic + completed streaming)
+      const local: ConversationTimelineTurn[] = session.localTurns.map(
         (turn, index) => ({
-          key: `persisted-${conversationId}-${turn.id}-${index}`,
+          key: `local-${conversationId}-${turn.id}-${index}`,
           turn,
           phase: "persisted",
         })
       )
+
+      // Phase 3: Optimistic turns (pending user messages)
       const optimistic: ConversationTimelineTurn[] =
         session.optimisticTurns.map((turn, index) => ({
           key: `optimistic-${conversationId}-${turn.id}-${index}`,
           turn,
           phase: "optimistic",
         }))
+
+      // Phase 4: Streaming turn (live agent response)
       const streamingMessage = session.liveMessage
       const streamingTurn = streamingMessage
         ? buildStreamingTurnFromLiveMessage(conversationId, streamingMessage)
         : null
 
-      if (!streamingTurn) {
-        return [...persisted, ...optimistic]
-      }
+      const result = [...persisted, ...local, ...optimistic]
 
-      return [
-        ...persisted,
-        ...optimistic,
-        {
+      if (streamingTurn) {
+        result.push({
           key: `streaming-${conversationId}-${streamingMessage?.id ?? "unknown"}`,
           turn: streamingTurn,
           phase: "streaming",
-        },
-      ]
+        })
+      }
+
+      return result
     },
     [state.byConversationId]
   )
 
-  const hydrateFromDetail = useCallback((detail: DbConversationDetail) => {
-    dispatch({ type: "HYDRATE_FROM_DETAIL", detail })
+  const fetchDetail = useCallback((conversationId: number) => {
+    const session = stateRef.current.byConversationId.get(conversationId)
+    if (session?.detail || session?.detailLoading) return
+
+    // Skip fetch if session has active data (ongoing conversation)
+    if (
+      session &&
+      (session.optimisticTurns.length > 0 ||
+        session.liveMessage !== null ||
+        session.localTurns.length > 0)
+    ) {
+      return
+    }
+
+    dispatch({ type: "FETCH_DETAIL_START", conversationId })
+    getFolderConversation(conversationId)
+      .then((detail) => {
+        dispatch({ type: "FETCH_DETAIL_SUCCESS", conversationId, detail })
+      })
+      .catch((error: unknown) => {
+        dispatch({
+          type: "FETCH_DETAIL_ERROR",
+          conversationId,
+          error: error instanceof Error ? error.message : String(error),
+        })
+      })
+  }, [])
+
+  const refetchDetail = useCallback((conversationId: number) => {
+    dispatch({ type: "FETCH_DETAIL_START", conversationId })
+    getFolderConversation(conversationId)
+      .then((detail) => {
+        dispatch({ type: "FETCH_DETAIL_SUCCESS", conversationId, detail })
+      })
+      .catch((error: unknown) => {
+        dispatch({
+          type: "FETCH_DETAIL_ERROR",
+          conversationId,
+          error: error instanceof Error ? error.message : String(error),
+        })
+      })
+  }, [])
+
+  const completeTurn = useCallback((conversationId: number) => {
+    dispatch({ type: "COMPLETE_TURN", conversationId })
   }, [])
 
   const appendOptimisticTurn = useCallback(
@@ -586,22 +630,6 @@ export function ConversationRuntimeProvider({
     []
   )
 
-  const acknowledgePersistedDetail = useCallback(
-    (
-      conversationId: number,
-      detail: DbConversationDetail,
-      turnToken?: string | null
-    ) => {
-      dispatch({
-        type: "ACK_PERSISTED_DETAIL",
-        conversationId,
-        detail,
-        turnToken,
-      })
-    },
-    []
-  )
-
   const setExternalId = useCallback(
     (conversationId: number, externalId: string | null) => {
       dispatch({ type: "SET_EXTERNAL_ID", conversationId, externalId })
@@ -627,6 +655,13 @@ export function ConversationRuntimeProvider({
     []
   )
 
+  const setPendingCleanup = useCallback(
+    (conversationId: number, pendingCleanup: boolean) => {
+      dispatch({ type: "SET_PENDING_CLEANUP", conversationId, pendingCleanup })
+    },
+    []
+  )
+
   const removeConversation = useCallback((conversationId: number) => {
     dispatch({ type: "REMOVE_CONVERSATION", conversationId })
   }, [])
@@ -640,13 +675,15 @@ export function ConversationRuntimeProvider({
       getSession,
       getConversationIdByExternalId,
       getTimelineTurns,
-      hydrateFromDetail,
+      fetchDetail,
+      refetchDetail,
+      completeTurn,
       appendOptimisticTurn,
       setLiveMessage,
-      acknowledgePersistedDetail,
       setExternalId,
       setSyncState,
       migrateConversation,
+      setPendingCleanup,
       removeConversation,
       reset,
     }),
@@ -654,13 +691,15 @@ export function ConversationRuntimeProvider({
       getSession,
       getConversationIdByExternalId,
       getTimelineTurns,
-      hydrateFromDetail,
+      fetchDetail,
+      refetchDetail,
+      completeTurn,
       appendOptimisticTurn,
       setLiveMessage,
-      acknowledgePersistedDetail,
       setExternalId,
       setSyncState,
       migrateConversation,
+      setPendingCleanup,
       removeConversation,
       reset,
     ]
diff --git a/src/hooks/use-conversation-detail.ts b/src/hooks/use-conversation-detail.ts
new file mode 100644
index 0000000..900dd30
--- /dev/null
+++ b/src/hooks/use-conversation-detail.ts
@@ -0,0 +1,39 @@
+"use client"
+
+import { useEffect } from "react"
+import { useConversationRuntime } from "@/contexts/conversation-runtime-context"
+import type { DbConversationDetail } from "@/lib/types"
+
+function isVirtualConversationId(conversationId: number): boolean {
+  return !Number.isFinite(conversationId) || conversationId <= 0
+}
+
+export function useConversationDetail(conversationId: number): {
+  detail: DbConversationDetail | null
+  loading: boolean
+  error: string | null
+} {
+  const { getSession, fetchDetail } = useConversationRuntime()
+  const session = getSession(conversationId)
+  const isVirtual = isVirtualConversationId(conversationId)
+
+  useEffect(() => {
+    if (isVirtual) return
+    if (session?.detail || session?.detailLoading) return
+    fetchDetail(conversationId)
+  }, [
+    conversationId,
+    isVirtual,
+    session?.detail,
+    session?.detailLoading,
+    fetchDetail,
+  ])
+
+  return {
+    detail: session?.detail ?? null,
+    loading: session
+      ? session.detailLoading
+      : !isVirtual,
+    error: session?.detailError ?? null,
+  }
+}
diff --git a/src/hooks/use-db-message-detail.ts b/src/hooks/use-db-message-detail.ts
deleted file mode 100644
index c325bb0..0000000
--- a/src/hooks/use-db-message-detail.ts
+++ /dev/null
@@ -1,208 +0,0 @@
-"use client"
-
-import { useCallback, useEffect, useMemo, useState } from "react"
-import { getFolderConversation } from "@/lib/tauri"
-import type { DbConversationDetail } from "@/lib/types"
-
-// Module-level cache: survives component unmount/remount
-const detailCache = new Map<number, DbConversationDetail>()
-const detailInFlight = new Map<number, Promise<DbConversationDetail>>()
-const detailListeners = new Map<
-  number,
-  Set<(detail: DbConversationDetail) => void>
->()
-
-function publishDetail(conversationId: number, detail: DbConversationDetail) {
-  const listeners = detailListeners.get(conversationId)
-  if (!listeners || listeners.size === 0) return
-  for (const listener of listeners) {
-    listener(detail)
-  }
-}
-
-function setCachedDetail(conversationId: number, detail: DbConversationDetail) {
-  detailCache.set(conversationId, detail)
-  publishDetail(conversationId, detail)
-}
-
-function subscribeDetail(
-  conversationId: number,
-  listener: (detail: DbConversationDetail) => void
-) {
-  let listeners = detailListeners.get(conversationId)
-  if (!listeners) {
-    listeners = new Set()
-    detailListeners.set(conversationId, listeners)
-  }
-  listeners.add(listener)
-
-  return () => {
-    const current = detailListeners.get(conversationId)
-    if (!current) return
-    current.delete(listener)
-    if (current.size === 0) {
-      detailListeners.delete(conversationId)
-    }
-  }
-}
-
-/** Invalidate cached detail so the next mount re-fetches from disk. */
-export function invalidateDetailCache(conversationId: number) {
-  detailCache.delete(conversationId)
-}
-
-async function loadAndCacheDetail(
-  conversationId: number
-): Promise<DbConversationDetail> {
-  const existing = detailInFlight.get(conversationId)
-  if (existing) return existing
-
-  const promise = getFolderConversation(conversationId)
-    .then((detail) => {
-      setCachedDetail(conversationId, detail)
-      return detail
-    })
-    .finally(() => {
-      detailInFlight.delete(conversationId)
-    })
-
-  detailInFlight.set(conversationId, promise)
-  return promise
-}
-
-export async function refreshDetailCache(
-  conversationId: number
-): Promise<DbConversationDetail> {
-  detailCache.delete(conversationId)
-  return loadAndCacheDetail(conversationId)
-}
-
-interface State {
-  key: number
-  detail: DbConversationDetail | null
-  loading: boolean
-  error: string | null
-  fetchSeq: number
-}
-
-function isVirtualConversationId(conversationId: number): boolean {
-  return !Number.isFinite(conversationId) || conversationId <= 0
-}
-
-export function useDbMessageDetail(conversationId: number) {
-  const isVirtualId = isVirtualConversationId(conversationId)
-  const getCachedState = useCallback((id: number): State => {
-    if (isVirtualConversationId(id)) {
-      return {
-        key: id,
-        detail: null,
-        loading: false,
-        error: null,
-        fetchSeq: 0,
-      }
-    }
-    const cached = detailCache.get(id)
-    return {
-      key: id,
-      detail: cached ?? null,
-      loading: !cached,
-      error: null,
-      fetchSeq: 0,
-    }
-  }, [])
-
-  const [state, setState] = useState<State>(() => {
-    return getCachedState(conversationId)
-  })
-
-  const derivedState =
-    state.key === conversationId ? state : getCachedState(conversationId)
-
-  useEffect(() => {
-    if (isVirtualId) return
-    return subscribeDetail(conversationId, (detail) => {
-      setState((prev) => ({
-        key: conversationId,
-        detail,
-        loading: false,
-        error: null,
-        fetchSeq: prev.key === conversationId ? prev.fetchSeq : 0,
-      }))
-    })
-  }, [conversationId, isVirtualId])
-
-  const refetch = useCallback(() => {
-    if (isVirtualConversationId(conversationId)) {
-      setState(getCachedState(conversationId))
-      return
-    }
-    detailCache.delete(conversationId)
-    setState((prev) => {
-      const base =
-        prev.key === conversationId ? prev : getCachedState(conversationId)
-      return {
-        ...base,
-        key: conversationId,
-        loading: true,
-        error: null,
-        fetchSeq: base.fetchSeq + 1,
-      }
-    })
-  }, [conversationId, getCachedState])
-
-  useEffect(() => {
-    if (isVirtualId) return
-    // Skip fetch if cache already has data
-    if (detailCache.has(conversationId)) return
-
-    let cancelled = false
-    loadAndCacheDetail(conversationId)
-      .then((d) => {
-        if (!cancelled) {
-          setState((prev) =>
-            prev.key === conversationId
-              ? { ...prev, detail: d, loading: false, error: null }
-              : {
-                  key: conversationId,
-                  detail: d,
-                  loading: false,
-                  error: null,
-                  fetchSeq: 0,
-                }
-          )
-        }
-      })
-      .catch((e) => {
-        if (!cancelled) {
-          setState((prev) =>
-            prev.key === conversationId
-              ? {
-                  ...prev,
-                  error: e instanceof Error ? e.message : String(e),
-                  loading: false,
-                }
-              : {
-                  key: conversationId,
-                  detail: null,
-                  loading: false,
-                  error: e instanceof Error ? e.message : String(e),
-                  fetchSeq: 0,
-                }
-          )
-        }
-      })
-    return () => {
-      cancelled = true
-    }
-  }, [conversationId, derivedState.fetchSeq, isVirtualId])
-
-  return useMemo(
-    () => ({
-      detail: derivedState.detail,
-      loading: derivedState.loading,
-      error: derivedState.error,
-      refetch,
-    }),
-    [derivedState.detail, derivedState.loading, derivedState.error, refetch]
-  )
-}
diff --git a/src/hooks/use-message-detail.ts b/src/hooks/use-message-detail.ts
deleted file mode 100644
index 05d6270..0000000
--- a/src/hooks/use-message-detail.ts
+++ /dev/null
@@ -1,60 +0,0 @@
-"use client"
-
-import { useEffect, useState } from "react"
-import { getConversation } from "@/lib/tauri"
-import type { AgentType, ConversationDetail } from "@/lib/types"
-
-interface MessageDetailState {
-  key: string
-  detail: ConversationDetail | null
-  loading: boolean
-  error: string | null
-}
-
-function makeKey(agentType: AgentType, conversationId: string): string {
-  return `${agentType}:${conversationId}`
-}
-
-export function useMessageDetail(agentType: AgentType, conversationId: string) {
-  const key = makeKey(agentType, conversationId)
-
-  const [state, setState] = useState<MessageDetailState>({
-    key,
-    detail: null,
-    loading: true,
-    error: null,
-  })
-
-  // Reset when key changes (single setState instead of 4)
-  if (state.key !== key) {
-    setState({ key, detail: null, loading: true, error: null })
-  }
-
-  useEffect(() => {
-    let cancelled = false
-    getConversation(agentType, conversationId)
-      .then((d) => {
-        if (!cancelled) {
-          setState((prev) => ({ ...prev, detail: d, loading: false }))
-        }
-      })
-      .catch((e) => {
-        if (!cancelled) {
-          setState((prev) => ({
-            ...prev,
-            error: e instanceof Error ? e.message : String(e),
-            loading: false,
-          }))
-        }
-      })
-    return () => {
-      cancelled = true
-    }
-  }, [agentType, conversationId])
-
-  return {
-    detail: state.detail,
-    loading: state.loading,
-    error: state.error,
-  }
-}
diff --git a/src/lib/adapters/ai-elements-adapter.ts b/src/lib/adapters/ai-elements-adapter.ts
index 4cd870e..f77a629 100644
--- a/src/lib/adapters/ai-elements-adapter.ts
+++ b/src/lib/adapters/ai-elements-adapter.ts
@@ -746,85 +746,3 @@ export function adaptMessageTurns(
     adaptMessageTurn(turn, text, streamingIndices?.has(i) ?? false)
   )
 }
-
-/**
- * A visual message group that merges consecutive assistant/tool turns
- * into a single block, split only by user or system messages.
- */
-export interface MessageGroup {
-  id: string
-  role: "user" | "assistant" | "system"
-  parts: AdaptedContentPart[]
-  userResources?: UserResourceDisplay[]
-  userImages?: UserImageDisplay[]
-  usage?: TurnUsage | null
-  duration_ms?: number | null
-  model?: string | null
-  models?: string[]
-}
-
-function mergeUsage(
-  a: TurnUsage | null | undefined,
-  b: TurnUsage | null | undefined
-): TurnUsage | null {
-  if (!a && !b) return null
-  if (!a) return b!
-  if (!b) return a
-  return {
-    input_tokens: a.input_tokens + b.input_tokens,
-    output_tokens: a.output_tokens + b.output_tokens,
-    cache_creation_input_tokens:
-      a.cache_creation_input_tokens + b.cache_creation_input_tokens,
-    cache_read_input_tokens:
-      a.cache_read_input_tokens + b.cache_read_input_tokens,
-  }
-}
-
-/**
- * Group adapted messages so that consecutive assistant/tool messages
- * are merged into one visual block, matching Claude Code terminal UX.
- */
-export function groupAdaptedMessages(
-  messages: AdaptedMessage[]
-): MessageGroup[] {
-  const groups: MessageGroup[] = []
-  let currentGroup: MessageGroup | null = null
-
-  for (const msg of messages) {
-    const effectiveRole = msg.role === "tool" ? "assistant" : msg.role
-
-    if (effectiveRole === "user" || effectiveRole === "system") {
-      currentGroup = null
-      groups.push({
-        id: msg.id,
-        role: effectiveRole,
-        parts: [...msg.content],
-        userResources: msg.userResources,
-        userImages: msg.userImages,
-      })
-    } else {
-      if (currentGroup && currentGroup.role === "assistant") {
-        currentGroup.parts.push(...msg.content)
-        currentGroup.usage = mergeUsage(currentGroup.usage, msg.usage)
-        currentGroup.duration_ms =
-          (currentGroup.duration_ms ?? 0) + (msg.duration_ms ?? 0)
-        if (msg.model && !currentGroup.models?.includes(msg.model)) {
-          currentGroup.models = [...(currentGroup.models ?? []), msg.model]
-        }
-      } else {
-        currentGroup = {
-          id: msg.id,
-          role: "assistant",
-          parts: [...msg.content],
-          usage: msg.usage,
-          duration_ms: msg.duration_ms,
-          model: msg.model,
-          models: msg.model ? [msg.model] : [],
-        }
-        groups.push(currentGroup)
-      }
-    }
-  }
-
-  return groups
-}
diff --git a/src/lib/types.ts b/src/lib/types.ts
index 362638e..dd54b57 100644
--- a/src/lib/types.ts
+++ b/src/lib/types.ts
@@ -80,13 +80,6 @@ export type ContentBlock =
     }
   | { type: "thinking"; text: string }
 
-export interface UnifiedMessage {
-  id: string
-  role: MessageRole
-  content: ContentBlock[]
-  timestamp: string
-}
-
 export type TurnRole = "user" | "assistant" | "system"
 
 export interface TurnUsage {