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/__init__.py

@@ -0,0 +1,73 @@
+"""Flask Application Factory."""
+import os
+
+from flask import Flask
+
+from config import config
+from app.extensions import cors, limiter, talisman, init_celery
+
+
+def create_app(config_name=None):
+    """Create and configure the Flask application."""
+    if config_name is None:
+        config_name = os.getenv("FLASK_ENV", "development")
+
+    app = Flask(__name__)
+    app.config.from_object(config[config_name])
+
+    # Create upload/output directories
+    os.makedirs(app.config["UPLOAD_FOLDER"], exist_ok=True)
+    os.makedirs(app.config["OUTPUT_FOLDER"], exist_ok=True)
+
+    # Initialize extensions
+    cors.init_app(app, origins=app.config["CORS_ORIGINS"])
+
+    limiter.init_app(app)
+
+    # Talisman security headers (relaxed CSP for AdSense)
+    csp = {
+        "default-src": "'self'",
+        "script-src": [
+            "'self'",
+            "'unsafe-inline'",
+            "https://pagead2.googlesyndication.com",
+            "https://www.googletagmanager.com",
+            "https://www.google-analytics.com",
+        ],
+        "style-src": ["'self'", "'unsafe-inline'", "https://fonts.googleapis.com"],
+        "font-src": ["'self'", "https://fonts.gstatic.com"],
+        "img-src": ["'self'", "data:", "https://pagead2.googlesyndication.com"],
+        "frame-src": ["https://googleads.g.doubleclick.net"],
+        "connect-src": [
+            "'self'",
+            "https://www.google-analytics.com",
+            "https://*.amazonaws.com",
+        ],
+    }
+    talisman.init_app(
+        app,
+        content_security_policy=csp,
+        force_https=config_name == "production",
+    )
+
+    # Initialize Celery
+    init_celery(app)
+
+    # Register blueprints
+    from app.routes.health import health_bp
+    from app.routes.convert import convert_bp
+    from app.routes.compress import compress_bp
+    from app.routes.image import image_bp
+    from app.routes.video import video_bp
+    from app.routes.tasks import tasks_bp
+    from app.routes.download import download_bp
+
+    app.register_blueprint(health_bp, url_prefix="/api")
+    app.register_blueprint(convert_bp, url_prefix="/api/convert")
+    app.register_blueprint(compress_bp, url_prefix="/api/compress")
+    app.register_blueprint(image_bp, url_prefix="/api/image")
+    app.register_blueprint(video_bp, url_prefix="/api/video")
+    app.register_blueprint(tasks_bp, url_prefix="/api/tasks")
+    app.register_blueprint(download_bp, url_prefix="/api/download")
+
+    return app