Implement Budgeting Page

Implement backend API endpoints for setting and fetching user budgets. Ensure users can set budget limits for different categories (e.g., groceries, entertainment). Create a user-friendly interface to display current budget limits and actual spending. Provide input fields for users to set or update their budget limits per category. Calculate the total spending in each category for the user and display it alongside their budget. Highlight categories where the user has exceeded their budget limit. Notify users if they are nearing or exceeding their budget for a specific category. Provide visual indicators (e.g., red for exceeding the budget) to show where they are overspending. Provide a summary of the user's overall spending vs. budget across all categories. Include graphs or charts to visualise how much of their budget has been used. Ensure the frontend fetches the user’s budget and spending data correctly from the API. Enable users to update their budgets, and reflect these changes in real-time. Ensure the page is easy to navigate and visually appealing.

Closes #9 (closed)