feat: DeepSeek V4 Flash 0731 added

src/app.rs

@@ -2566,6 +2566,7 @@ mod tests {
             Some(Message::FocusPrevious)
         ));
         assert!(ModelChoice::DeepSeekV4Flash.supports_dspark());
+        assert!(!ModelChoice::DeepSeekV4Flash0731.supports_dspark());
         assert!(!ModelChoice::DeepSeekV4Pro.supports_dspark());
         assert!(!ModelChoice::Glm52.supports_dspark());
     }