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/tests/test_image.py

@@ -0,0 +1,27 @@
+"""Tests for image conversion & resize endpoints."""
+import io
+
+
+def test_image_convert_no_file(client):
+    """POST /api/image/convert without file should return 400."""
+    response = client.post('/api/image/convert')
+    assert response.status_code == 400
+
+
+def test_image_resize_no_file(client):
+    """POST /api/image/resize without file should return 400."""
+    response = client.post('/api/image/resize')
+    assert response.status_code == 400
+
+
+def test_image_convert_wrong_type(client):
+    """POST /api/image/convert with non-image should return 400."""
+    data = {
+        'file': (io.BytesIO(b'not an image'), 'test.pdf'),
+    }
+    response = client.post(
+        '/api/image/convert',
+        data=data,
+        content_type='multipart/form-data',
+    )
+    assert response.status_code == 400