Add blueprints for authentication, admin, dashboard, gallery, generation, and profile routes

- Created `__init__.py` for blueprint registration.
- Implemented `auth.py` for user authentication (login, register, logout).
- Added `admin.py` for admin functionalities (user management, stats).
- Developed `dashboard.py` for user dashboard displaying user info and generated content.
- Created `gallery.py` for managing and displaying images and videos.
- Implemented `generate.py` for text, image, and video generation functionalities.
- Added `profile.py` for user profile management.
- Updated templates to reflect new route structures and improve navigation.

frontend/app/__init__.py

@@ -0,0 +1,17 @@
+"""Flask frontend application factory."""
+from flask import Flask
+
+from .config import Config
+from .filters import register_filters
+from .routes import register_blueprints
+
+
+def create_app() -> Flask:
+    """Create and configure the Flask application."""
+    app = Flask(__name__)
+    app.config.from_object(Config)
+
+    register_filters(app)
+    register_blueprints(app)
+
+    return app