Refactor project structure and implement new features

- Removed unused security module and updated import paths.
- Enhanced OpenAI client with streaming capabilities for chat completions.
- Added new backend API endpoints for health check (ping).
- Established a new FastAPI application with CORS configuration.
- Created a new Appshell component for the frontend with navigation links.
- Integrated SVG icons and improved styling for the Appshell component.
- Implemented memory management for conversation history using PostgreSQL.
- Developed abstract classes for AI agents and models, with OpenAI integration.
- Added encryption utilities for secure data handling.

frontend/tsconfig.json

@@ -21,5 +21,5 @@
       "@test-utils": ["./test-utils"]
     }
   },
-  "include": ["src", "test-utils"]
+  "include": ["src", "src/types", "test-utils"]
 }