Show logged in user in title bar

[sirnails]

Show logged in user in title bar

[sirnails]

feat: Add getUserInfo method and enhance navbar user display

• Added getUserInfo method in UserController to retrieve user information by user ID.
• Updated User model to include getUserById method for fetching user details from the database.
• Enhanced the navbar to display the logged-in user's username upon successful login.
• Refactored the navbar code to properly initialize the UserController and fetch user information if a user session exists.
• Implemented a global exception handler in index.php for improved error logging and handling.
• Ensured InputHelper is required after establishing database and controller dependencies to maintain proper load order.