feat: add multi-file type support for Gemini and Claude

- Add file data DTO for structured file handling
- Implement file decoder service
- Update Claude and Gemini relay channels to handle various file types
- Reorganize worker service to cf_worker for clarity
- Update token counter and image service for new file types

dto/file_data.go

@@ -0,0 +1,8 @@
+package dto
+
+type LocalFileData struct {
+	MimeType   string
+	Base64Data string
+	Url        string
+	Size       int64
+}