feat: Initialize frontend with React, Vite, and Tailwind CSS

- Set up main entry point for React application.
- Create About, Home, NotFound, Privacy, and Terms pages with SEO support.
- Implement API service for file uploads and task management.
- Add global styles using Tailwind CSS.
- Create utility functions for SEO and text processing.
- Configure Vite for development and production builds.
- Set up Nginx configuration for serving frontend and backend.
- Add scripts for cleanup of expired files and sitemap generation.
- Implement deployment script for production environment.

backend/app/tasks/convert_tasks.py

@@ -0,0 +1,128 @@
+"""Celery tasks for PDF conversion (PDF↔Word)."""
+import os
+import logging
+
+from app.extensions import celery
+from app.services.pdf_service import pdf_to_word, word_to_pdf, PDFConversionError
+from app.services.storage_service import storage
+from app.utils.sanitizer import cleanup_task_files
+
+
+def _cleanup(task_id: str):
+    """Cleanup with local-aware flag."""
+    cleanup_task_files(task_id, keep_outputs=not storage.use_s3)
+
+logger = logging.getLogger(__name__)
+
+
+@celery.task(bind=True, name="app.tasks.convert_tasks.convert_pdf_to_word")
+def convert_pdf_to_word(self, input_path: str, task_id: str, original_filename: str):
+    """
+    Async task: Convert PDF to Word document.
+
+    Args:
+        input_path: Path to the uploaded PDF file
+        task_id: Unique task identifier
+        original_filename: Original filename for download
+
+    Returns:
+        dict with download_url and file info
+    """
+    output_dir = os.path.join("/tmp/outputs", task_id)
+
+    try:
+        self.update_state(state="PROCESSING", meta={"step": "Converting PDF to Word..."})
+
+        # Convert using LibreOffice
+        output_path = pdf_to_word(input_path, output_dir)
+
+        self.update_state(state="PROCESSING", meta={"step": "Uploading result..."})
+
+        # Upload to S3
+        s3_key = storage.upload_file(output_path, task_id, folder="outputs")
+
+        # Generate download filename
+        name_without_ext = os.path.splitext(original_filename)[0]
+        download_name = f"{name_without_ext}.docx"
+
+        # Generate presigned URL
+        download_url = storage.generate_presigned_url(
+            s3_key, original_filename=download_name
+        )
+
+        result = {
+            "status": "completed",
+            "download_url": download_url,
+            "filename": download_name,
+            "output_size": os.path.getsize(output_path),
+        }
+
+        # Cleanup local files
+        _cleanup(task_id)
+
+        logger.info(f"Task {task_id}: PDF→Word conversion completed")
+        return result
+
+    except PDFConversionError as e:
+        logger.error(f"Task {task_id}: Conversion error — {e}")
+        _cleanup(task_id)
+        return {"status": "failed", "error": str(e)}
+
+    except Exception as e:
+        logger.error(f"Task {task_id}: Unexpected error — {e}")
+        _cleanup(task_id)
+        return {"status": "failed", "error": "An unexpected error occurred."}
+
+
+@celery.task(bind=True, name="app.tasks.convert_tasks.convert_word_to_pdf")
+def convert_word_to_pdf(self, input_path: str, task_id: str, original_filename: str):
+    """
+    Async task: Convert Word document to PDF.
+
+    Args:
+        input_path: Path to the uploaded Word file
+        task_id: Unique task identifier
+        original_filename: Original filename for download
+
+    Returns:
+        dict with download_url and file info
+    """
+    output_dir = os.path.join("/tmp/outputs", task_id)
+
+    try:
+        self.update_state(state="PROCESSING", meta={"step": "Converting Word to PDF..."})
+
+        output_path = word_to_pdf(input_path, output_dir)
+
+        self.update_state(state="PROCESSING", meta={"step": "Uploading result..."})
+
+        s3_key = storage.upload_file(output_path, task_id, folder="outputs")
+
+        name_without_ext = os.path.splitext(original_filename)[0]
+        download_name = f"{name_without_ext}.pdf"
+
+        download_url = storage.generate_presigned_url(
+            s3_key, original_filename=download_name
+        )
+
+        result = {
+            "status": "completed",
+            "download_url": download_url,
+            "filename": download_name,
+            "output_size": os.path.getsize(output_path),
+        }
+
+        _cleanup(task_id)
+
+        logger.info(f"Task {task_id}: Word→PDF conversion completed")
+        return result
+
+    except PDFConversionError as e:
+        logger.error(f"Task {task_id}: Conversion error — {e}")
+        _cleanup(task_id)
+        return {"status": "failed", "error": str(e)}
+
+    except Exception as e:
+        logger.error(f"Task {task_id}: Unexpected error — {e}")
+        _cleanup(task_id)
+        return {"status": "failed", "error": "An unexpected error occurred."}