refactor: migrate styles to Tailwind and clean up components

- remove SCSS style files for ChatQuickAccess and ChatInputArea, replace with inline Tailwind utilities
- uncomment ChatQuickAccess component in ChatMainList to re-enable the quick access bar
- simplify speech recognition logic in ChatInputArea, update input placeholder text
- replace direct uni.showToast calls with a shared helper function
- remove unused keyboard height change listener and redundant keyboard hiding code

src/pages/home/components/ChatMainList/index.vue

@@ -119,12 +119,12 @@
     </div>
 
     <!-- 输入框区域 -->
-    <!-- <div>
+    <div>
       <ChatQuickAccess />
       <ChatInputArea ref="inputAreaRef" v-model="inputMessage" :holdKeyboard="holdKeyboard"
         :is-session-active="isSessionActive" :stop-request="stopRequest" @send="sendMessageAction"
         @noHideKeyboard="handleNoHideKeyboard" @keyboardShow="handleKeyboardShow" @keyboardHide="handleKeyboardHide" />
-    </div> -->
+    </div>
   </div>
 </template>