Add OCR, Background Removal, and PDF Editor features with tests

- Implemented OCR functionality using pytesseract for image and PDF text extraction.
- Added Background Removal service using rembg for image processing.
- Developed PDF Editor service for applying text annotations to PDF files.
- Created corresponding API routes for OCR, Background Removal, and PDF Editor.
- Added frontend components for OCR and Background Removal tools.
- Integrated feature flagging for new tools, ensuring they are disabled by default.
- Implemented comprehensive unit tests for OCR service, PDF editor, and background removal.
- Updated documentation to reflect new features and usage instructions.
- Added translations for new features in English, Arabic, and French.

backend/app/extensions.py

@@ -32,6 +32,9 @@ def init_celery(app):
         "app.tasks.video_tasks.*": {"queue": "video"},
         "app.tasks.pdf_tools_tasks.*": {"queue": "pdf_tools"},
         "app.tasks.flowchart_tasks.*": {"queue": "flowchart"},
+        "app.tasks.ocr_tasks.*": {"queue": "image"},
+        "app.tasks.removebg_tasks.*": {"queue": "image"},
+        "app.tasks.pdf_editor_tasks.*": {"queue": "pdf_tools"},
     }
 
     # Celery Beat — periodic tasks