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/utils/cleanup.py

@@ -0,0 +1,31 @@
+"""Scheduled cleanup of expired temporary files."""
+import os
+import shutil
+import time
+
+from flask import current_app
+
+
+def cleanup_expired_files():
+    """Remove files older than FILE_EXPIRY_SECONDS from upload/output dirs."""
+    expiry = current_app.config.get("FILE_EXPIRY_SECONDS", 1800)
+    now = time.time()
+    removed_count = 0
+
+    for folder_key in ["UPLOAD_FOLDER", "OUTPUT_FOLDER"]:
+        folder = current_app.config.get(folder_key)
+        if not folder or not os.path.exists(folder):
+            continue
+
+        for task_dir_name in os.listdir(folder):
+            task_dir = os.path.join(folder, task_dir_name)
+            if not os.path.isdir(task_dir):
+                continue
+
+            # Check directory age based on modification time
+            dir_mtime = os.path.getmtime(task_dir)
+            if now - dir_mtime > expiry:
+                shutil.rmtree(task_dir, ignore_errors=True)
+                removed_count += 1
+
+    return removed_count