Realization of trees, calculation of prefix expression on C#

Our company is engaged in selling goods online and needs to develop an internal system for automating warehouse operations. It is necessary to create an application in C# that will allow employees to control the receipt, storage, and issuance of goods. The main goal of the project: To develop user-friendly software that simplifies inventory management, reduces errors when processing orders, and allows for quick access to information about the warehouse status. Main requirements for the project: Development of the application in C# Use the .NET platform (preferably .NET 8 or higher). The code must be structured and adhere to OOP principles. A clear project architecture must be used. System functionality: User authentication (administrator, warehouse employee). Adding, editing, and deleting products. Viewing the product list with search and filtering options. Tracking the quantity of goods in the warehouse. Registering the receipt and issuance of products. Generating reports on product inventory. Saving data in a database (e.g., SQL Server or PostgreSQL). Application interface: Create a user-friendly interface. Implementation may be in the form of: A WPF application for Windows; An ASP.NET Core web application; Or another solution by agreement. Additional requirements: Error handling and exceptional situation management. User action logging. Possibility for further functionality expansion. Provision of a project launch instruction. What needs to be provided upon completion: Source code of the project. Database file or scripts for creating the database. Description of the program architecture. Installation and launch instructions. A brief presentation of the implemented functionality. Deadline: To be discussed with the contractor after assessing the scope of work. Acceptance criteria: The project runs successfully without errors. All declared functions work correctly. The code meets quality and readability standards. The application is ready for further development.

It is necessary to add animation to the low-poly main character and give him the ability to hold a weapon (tool) that will aim at the cursor. The game is from a third-person perspective, with the camera behind the player and the cursor in the center of the screen. The character needs to be able to enter aim mode, the camera slightly zooms in, and the character should be able to use the tool (a laser tool for resource gathering). I have a ready animation controller from Synty - Third Person Controller. It can be used or the animation can be completely set up from scratch if that is easier. In the end, I expect a character that can select a tool (one large two-handed and two small ones), switch tools, aim, and have the head and the tool look at the point where the cursor is pointing.