refactor: enhance multi-selection handling in Inputbar and MessageEditor

- Integrated `useAppSelector` in Inputbar to manage multi-selection state.
- Updated Inputbar to conditionally render based on multi-selection mode.
- Modified MessageEditor to display the resend button only for assistant messages, improving UI clarity.

src/renderer/src/components/Popups/MultiSelectionPopup.tsx

@@ -53,14 +53,10 @@ const MultiSelectActionPopup: FC<Props> = ({ topic }) => {
 }
 
 const Container = styled.div`
-  position: absolute;
-  bottom: 0;
-  left: 0;
   width: 100%;
   padding: 36px 20px;
   background-color: var(--color-background);
   border-top: 1px solid var(--color-border);
-  z-index: 10;
 `
 
 const ActionBar = styled.div`

src/renderer/src/pages/home/Inputbar/Inputbar.tsx

@@ -27,7 +27,7 @@ import PasteService from '@renderer/services/PasteService'
 import { estimateTextTokens as estimateTxtTokens, estimateUserPromptUsage } from '@renderer/services/TokenService'
 import { translateText } from '@renderer/services/TranslateService'
 import WebSearchService from '@renderer/services/WebSearchService'
-import { useAppDispatch } from '@renderer/store'
+import { useAppDispatch, useAppSelector } from '@renderer/store'
 import { setSearching } from '@renderer/store/runtime'
 import { sendMessage as _sendMessage } from '@renderer/store/thunk/messageThunk'
 import { Assistant, FileType, KnowledgeBase, KnowledgeItem, Model, Topic } from '@renderer/types'
@@ -127,6 +127,7 @@ const Inputbar: FC<Props> = ({ assistant: _assistant, setActiveTopic, topic }) =
   const supportExts = useMemo(() => [...textExts, ...documentExts, ...(isVision ? imageExts : [])], [isVision])
   const { activedMcpServers } = useMCPServers()
   const { bases: knowledgeBases } = useKnowledgeBases()
+  const isMultiSelectMode = useAppSelector((state) => state.runtime.chat.isMultiSelectMode)
 
   const quickPanel = useQuickPanel()
 
@@ -869,6 +870,10 @@ const Inputbar: FC<Props> = ({ assistant: _assistant, setActiveTopic, topic }) =
   const isExpended = expended || !!textareaHeight
   const showThinkingButton = isSupportedThinkingTokenModel(model) || isSupportedReasoningEffortModel(model)
 
+  if (isMultiSelectMode) {
+    return null
+  }
+
   return (
     <Container
       onDragOver={handleDragOver}

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

@@ -255,11 +255,13 @@ const MessageBlockEditor: FC<Props> = ({ message, onSave, onResend, onCancel })
               <Save size={16} />
             </ToolbarButton>
           </Tooltip>
-          <Tooltip title={t('chat.resend')}>
-            <ToolbarButton type="text" onClick={() => handleClick(true)}>
-              <Send size={16} />
-            </ToolbarButton>
-          </Tooltip>
+          {message.role === 'assistant' && (
+            <Tooltip title={t('chat.resend')}>
+              <ToolbarButton type="text" onClick={() => handleClick(true)}>
+                <Send size={16} />
+              </ToolbarButton>
+            </Tooltip>
+          )}
         </ActionBarRight>
       </ActionBar>
     </EditorContainer>