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.

scripts/cleanup_expired_files.py

@@ -0,0 +1,85 @@
+#!/usr/bin/env python3
+"""
+cleanup_expired_files.py
+Removes expired upload/output files older than FILE_EXPIRY_SECONDS.
+
+Usage:
+  python scripts/cleanup_expired_files.py            # Dry run
+  python scripts/cleanup_expired_files.py --execute   # Actually delete
+"""
+
+import os
+import sys
+import time
+import shutil
+import argparse
+
+# Default to 2 hours
+DEFAULT_EXPIRY_SECONDS = 7200
+UPLOAD_DIR = os.path.join(os.path.dirname(__file__), '..', 'backend', 'uploads')
+
+
+def cleanup(upload_dir: str, expiry_seconds: int, dry_run: bool = True) -> dict:
+    """Remove directories older than expiry_seconds."""
+    now = time.time()
+    stats = {'scanned': 0, 'deleted': 0, 'freed_bytes': 0, 'errors': 0}
+
+    if not os.path.isdir(upload_dir):
+        print(f"Upload directory does not exist: {upload_dir}")
+        return stats
+
+    for entry in os.listdir(upload_dir):
+        full_path = os.path.join(upload_dir, entry)
+        if not os.path.isdir(full_path):
+            continue
+
+        stats['scanned'] += 1
+        mod_time = os.path.getmtime(full_path)
+        age = now - mod_time
+
+        if age > expiry_seconds:
+            # Calculate size
+            dir_size = sum(
+                os.path.getsize(os.path.join(dp, f))
+                for dp, _, filenames in os.walk(full_path)
+                for f in filenames
+            )
+
+            if dry_run:
+                print(f"[DRY RUN] Would delete: {entry} (age: {age:.0f}s, size: {dir_size / 1024:.1f} KB)")
+            else:
+                try:
+                    shutil.rmtree(full_path)
+                    print(f"Deleted: {entry} (age: {age:.0f}s, size: {dir_size / 1024:.1f} KB)")
+                    stats['deleted'] += 1
+                    stats['freed_bytes'] += dir_size
+                except Exception as e:
+                    print(f"Error deleting {entry}: {e}")
+                    stats['errors'] += 1
+
+    return stats
+
+
+def main():
+    parser = argparse.ArgumentParser(description='Cleanup expired upload files')
+    parser.add_argument('--execute', action='store_true', help='Actually delete files (default is dry run)')
+    parser.add_argument('--expiry', type=int, default=DEFAULT_EXPIRY_SECONDS, help='Expiry time in seconds')
+    parser.add_argument('--dir', type=str, default=UPLOAD_DIR, help='Upload directory path')
+    args = parser.parse_args()
+
+    dry_run = not args.execute
+    if dry_run:
+        print("=== DRY RUN MODE (use --execute to delete) ===\n")
+
+    stats = cleanup(args.dir, args.expiry, dry_run)
+
+    print(f"\n--- Summary ---")
+    print(f"Scanned: {stats['scanned']} directories")
+    print(f"Deleted: {stats['deleted']} directories")
+    print(f"Freed:   {stats['freed_bytes'] / 1024 / 1024:.2f} MB")
+    if stats['errors']:
+        print(f"Errors:  {stats['errors']}")
+
+
+if __name__ == '__main__':
+    main()