feat: enhance tag formatting options

- Update formatting to replace spaces with underscores
- Add functionality to replace hyphens with underscores
- Clarify comments to reflect new formatting behavior

These changes improve the flexibility of the tag formatting method by
allowing both spaces and hyphens to be standardized as underscores,
ensuring consistent tag representations.

app/helpers/tag_helper.rb

@@ -2,8 +2,9 @@ module TagHelper
   def format_as_tag(text)
     return nil if text.blank?
 
-    # 下划线方式 (选项1)
+    # 空格改为下划线
     text.strip.gsub(/\s+/, "_")
+    text.strip.gsub("-", "_")
 
     # 或者删除空格 (选项2)
     # text.strip.gsub(/\s+/, '')