refactor(ChatScreen): update text colors for dark mode compatibility

- Modified text color styles in SegmentRenderer and styles.ts to utilize theme colors for better adaptability in dark mode.
- Updated bubble colors in palettes.ts to enhance visual consistency across chat components.

src/screens/message/components/ChatScreen/styles.ts

@@ -227,7 +227,7 @@ export function createChatScreenStyles(colors: AppColors) {
   },
   senderName: {
     fontSize: 14,
-    color: '#555555', // 柔和的深灰色
+    color: colors.chat.textSecondary, // 使用主题次要文字颜色
     marginBottom: 4,
     marginLeft: 4,
     fontWeight: '600',
@@ -272,14 +272,14 @@ export function createChatScreenStyles(colors: AppColors) {
     borderStyle: 'dashed',
   },
   myBubbleText: {
-    color: '#2A2A2A',
-    fontSize: 18,     // 更大字体
-    lineHeight: 25,   // 相应调大行高
+    color: colors.chat.textPrimary,  // 使用主题文字颜色
+    fontSize: 18,
+    lineHeight: 25,
     letterSpacing: 0.1,
     fontWeight: '400',
   },
   theirBubbleText: {
-    color: '#2A2A2A',
+    color: colors.chat.textPrimary,  // 使用主题文字颜色
     fontSize: 18,
     lineHeight: 25,
     letterSpacing: 0.1,