feat/调整tts音色，调整封面图prompt，修复对话页输入框显示逻辑，待验证封面图生成功能

app-expo/src/app/(main)/conversation/[id].tsx

@@ -15,6 +15,7 @@ import {
   Animated,
   FlatList,
   InteractionManager,
+  Keyboard,
   KeyboardAvoidingView,
   Platform,
   Pressable,
@@ -578,8 +579,20 @@ export default function ConversationScreen() {
 
   const [input, setInput] = useState('');
   const [inputMode, setInputMode] = useState<InputMode>('text');
+  const [isKeyboardVisible, setIsKeyboardVisible] = useState(false);
   const listRef = useRef<FlatList>(null);
 
+  useEffect(() => {
+    const onShow = () => setIsKeyboardVisible(true);
+    const onHide = () => setIsKeyboardVisible(false);
+    const subShow = Keyboard.addListener('keyboardDidShow', onShow);
+    const subHide = Keyboard.addListener('keyboardDidHide', onHide);
+    return () => {
+      subShow.remove();
+      subHide.remove();
+    };
+  }, []);
+
   const flattenedData = flattenMessagesForList(messages ?? []);
 
   const isRecording = recorderStatus === 'recording';
@@ -607,11 +620,12 @@ export default function ConversationScreen() {
         : t('connectionDisconnected');
 
   const keyboardOffset = Platform.OS === 'ios' ? insets.top + 56 : 0;
+  const kavEnabled = inputMode === 'text' && isKeyboardVisible;
 
   return (
     <KeyboardAvoidingView
       style={styles.container}
-      behavior="padding"
+      behavior={kavEnabled ? 'padding' : undefined}
       keyboardVerticalOffset={keyboardOffset}
     >
       <View style={styles.column}>
@@ -694,9 +708,14 @@ export default function ConversationScreen() {
             onChangeText={setInput}
             onSend={handleSend}
             inputMode={inputMode}
-            onInputModeToggle={() =>
-              setInputMode((m) => (m === 'text' ? 'voice' : 'text'))
-            }
+            onInputModeToggle={() => {
+              setInputMode((m) => {
+                if (m === 'text') {
+                  Keyboard.dismiss();
+                }
+                return m === 'text' ? 'voice' : 'text';
+              });
+            }}
             onAddPress={() => {}}
             onStartRecording={handleStartRecording}
             onStopRecording={() => void stopRecording()}