Refactor agent session messages to use shared hook and implement batch deletion

- Replace manual Redux logic with `useTopicMessages` hook for consistent message loading behavior
- Add `deleteMessages` method to message data sources with proper block and file cleanup
- Update `DbService` to delegate batch deletion to appropriate data source implementations

src/renderer/src/pages/home/Messages/AgentSessionMessages.tsx

@@ -1,13 +1,11 @@
 import { loggerService } from '@logger'
 import ContextMenu from '@renderer/components/ContextMenu'
 import { useSession } from '@renderer/hooks/agents/useSession'
+import { useTopicMessages } from '@renderer/hooks/useMessageOperations'
 import { getGroupedMessages } from '@renderer/services/MessagesService'
-import { useAppDispatch, useAppSelector } from '@renderer/store'
-import { selectMessagesForTopic } from '@renderer/store/newMessage'
-import { loadTopicMessagesThunk } from '@renderer/store/thunk/messageThunk'
-import { Topic } from '@renderer/types'
+import { type Topic, TopicType } from '@renderer/types'
 import { buildAgentSessionTopicId } from '@renderer/utils/agentSession'
-import { memo, useEffect, useMemo } from 'react'
+import { memo, useMemo } from 'react'
 import styled from 'styled-components'
 
 import MessageGroup from './MessageGroup'
@@ -22,23 +20,10 @@ type Props = {
 }
 
 const AgentSessionMessages: React.FC<Props> = ({ agentId, sessionId }) => {
-  const dispatch = useAppDispatch()
   const { session } = useSession(agentId, sessionId)
   const sessionTopicId = useMemo(() => buildAgentSessionTopicId(sessionId), [sessionId])
-  const messages = useAppSelector((state) => selectMessagesForTopic(state, sessionTopicId))
-
-  // Load messages when session changes or when messages are empty
-  useEffect(() => {
-    if (sessionId) {
-      // Only load if we don't have messages yet
-      // This prevents overwriting messages that were just added
-      const hasMessages = messages && messages.length > 0
-      if (!hasMessages) {
-        logger.info('Loading messages for agent session', { sessionId })
-        dispatch(loadTopicMessagesThunk(sessionTopicId, false)) // Don't force reload if we have messages in Redux
-      }
-    }
-  }, [dispatch, sessionId, sessionTopicId, messages?.length])
+  // Use the same hook as Messages.tsx for consistent behavior
+  const messages = useTopicMessages(sessionTopicId)
 
   const displayMessages = useMemo(() => {
     if (!messages || messages.length === 0) return []
@@ -58,6 +43,7 @@ const AgentSessionMessages: React.FC<Props> = ({ agentId, sessionId }) => {
   const derivedTopic = useMemo<Topic>(
     () => ({
       id: sessionTopicId,
+      type: TopicType.Session,
       assistantId: sessionAssistantId,
       name: sessionName,
       createdAt: sessionCreatedAt,

src/renderer/src/services/db/AgentMessageDataSource.ts

@@ -373,6 +373,15 @@ export class AgentMessageDataSource implements MessageDataSource {
     // 2. Or just hide from UI without actual deletion
   }
 
+  async deleteMessages(topicId: string, _messageIds: string[]): Promise<void> {
+    // Agent session messages cannot be deleted in batch
+    logger.warn(`deleteMessages called for agent session ${topicId}, operation not supported`)
+
+    // In a full implementation, you might want to:
+    // 1. Implement batch soft delete in backend
+    // 2. Update local state accordingly
+  }
+
   async deleteMessagesByAskId(topicId: string, _askId: string): Promise<void> {
     // Agent session messages cannot be deleted
     logger.warn(`deleteMessagesByAskId called for agent session ${topicId}, operation not supported`)

src/renderer/src/services/db/DbService.ts

@@ -86,9 +86,9 @@ class DbService implements MessageDataSource {
     return source.deleteMessage(topicId, messageId)
   }
 
-  async deleteMessagesByAskId(topicId: string, askId: string): Promise<void> {
+  async deleteMessages(topicId: string, messageIds: string[]): Promise<void> {
     const source = this.getDataSource(topicId)
-    return source.deleteMessagesByAskId(topicId, askId)
+    return source.deleteMessages(topicId, messageIds)
   }
 
   // ============ Block Operations ============

src/renderer/src/services/db/DexieMessageDataSource.ts

@@ -203,39 +203,48 @@ export class DexieMessageDataSource implements MessageDataSource {
     }
   }
 
-  async deleteMessagesByAskId(topicId: string, askId: string): Promise<void> {
+  async deleteMessages(topicId: string, messageIds: string[]): Promise<void> {
     try {
       await db.transaction('rw', db.topics, db.message_blocks, db.files, async () => {
         const topic = await db.topics.get(topicId)
         if (!topic) return
 
-        // Find all messages with the given askId
-        const messagesToDelete = topic.messages.filter((m) => m.askId === askId || m.id === askId)
-        const blockIdsToDelete = messagesToDelete.flatMap((m) => m.blocks || [])
+        // Collect all block IDs from messages to be deleted
+        const allBlockIds: string[] = []
+        const messagesToDelete: Message[] = []
+
+        for (const messageId of messageIds) {
+          const message = topic.messages.find((m) => m.id === messageId)
+          if (message) {
+            messagesToDelete.push(message)
+            if (message.blocks && message.blocks.length > 0) {
+              allBlockIds.push(...message.blocks)
+            }
+          }
+        }
 
         // Delete blocks and handle files
-        if (blockIdsToDelete.length > 0) {
-          const blocks = await db.message_blocks.where('id').anyOf(blockIdsToDelete).toArray()
+        if (allBlockIds.length > 0) {
+          const blocks = await db.message_blocks.where('id').anyOf(allBlockIds).toArray()
           const files = blocks
             .filter((block) => block.type === 'file' || block.type === 'image')
             .map((block: any) => block.file)
             .filter((file) => file !== undefined)
 
+          // Clean up files
           if (!isEmpty(files)) {
             await Promise.all(files.map((file) => FileManager.deleteFile(file.id, false)))
           }
-
-          await db.message_blocks.bulkDelete(blockIdsToDelete)
+          await db.message_blocks.bulkDelete(allBlockIds)
         }
 
-        // Filter out deleted messages
-        const remainingMessages = topic.messages.filter((m) => m.askId !== askId && m.id !== askId)
+        // Remove messages from topic
+        const remainingMessages = topic.messages.filter((m) => !messageIds.includes(m.id))
         await db.topics.update(topicId, { messages: remainingMessages })
       })
-
       store.dispatch(updateTopicUpdatedAt({ topicId }))
     } catch (error) {
-      logger.error(`Failed to delete messages with askId ${askId} from topic ${topicId}:`, error as Error)
+      logger.error(`Failed to delete messages from topic ${topicId}:`, error as Error)
       throw error
     }
   }

src/renderer/src/services/db/types.ts

@@ -64,9 +64,9 @@ export interface MessageDataSource {
   deleteMessage(topicId: string, messageId: string): Promise<void>
 
   /**
-   * Delete messages by askId (user query + assistant responses)
+   * Delete multiple messages and their blocks
    */
-  deleteMessagesByAskId(topicId: string, askId: string): Promise<void>
+  deleteMessages(topicId: string, messageIds: string[]): Promise<void>
 
   // ============ Block Operations ============
   /**

src/renderer/src/store/thunk/messageThunk.v2.ts

@@ -5,10 +5,7 @@
 
 import { loggerService } from '@logger'
 import { dbService } from '@renderer/services/db'
-import type { Topic } from '@renderer/types'
-import { TopicType } from '@renderer/types'
 import type { Message, MessageBlock } from '@renderer/types/newMessage'
-import { isAgentSessionTopicId } from '@renderer/utils/agentSession'
 
 import type { AppDispatch, RootState } from '../index'
 import { upsertManyBlocks } from '../messageBlock'
@@ -80,42 +77,6 @@ export const getRawTopicV2 = async (topicId: string): Promise<{ id: string; mess
 // Phase 2.2 - Batch 2: Helper functions
 // =================================================================
 
-/**
- * Get a full topic object with type information
- * This builds on getRawTopicV2 to provide additional metadata
- */
-export const getTopicV2 = async (topicId: string): Promise<Topic | undefined> => {
-  try {
-    const rawTopic = await dbService.getRawTopic(topicId)
-    if (!rawTopic) {
-      logger.info('Topic not found', { topicId })
-      return undefined
-    }
-
-    // Construct the full Topic object
-    const topic: Topic = {
-      id: rawTopic.id,
-      type: isAgentSessionTopicId(topicId) ? TopicType.Session : TopicType.Chat,
-      messages: rawTopic.messages,
-      assistantId: '', // These fields would need to be fetched from appropriate source
-      name: '',
-      createdAt: Date.now(),
-      updatedAt: Date.now()
-    }
-
-    logger.info('Retrieved topic with type via DbService', {
-      topicId,
-      type: topic.type,
-      messageCount: topic.messages.length
-    })
-
-    return topic
-  } catch (error) {
-    logger.error('Failed to get topic:', { topicId, error })
-    return undefined
-  }
-}
-
 /**
  * Update file reference count
  * Only applies to Dexie data source, no-op for agent sessions