fix(file): Remove illegal chars in file_name

- / and \ cannot work as file names
- % is not allowed verbatim in URLs
- ? and # are not allowed because confused with query/hash separators

frappe/core/doctype/file/file.py

@@ -675,7 +675,7 @@ class File(Document):
 			return self.save_file_on_filesystem()
 
 	def save_file_on_filesystem(self):
-		safe_file_name = self.file_name.replace("%", "_")
+		safe_file_name = re.sub(r"[/\\%?#]", "_", self.file_name)
 		if self.is_private:
 			self.file_url = f"/private/files/{safe_file_name}"
 		else: