Feature Req: Setting Budgets & alerts Closes #4

[adithyen]

…edit/delete bugs

📌 Description

Brief description of what this PR does.
To add a feature for setting monthly budget and show warnings when close/exceeded (may be through notification or home screen UI ).

🔗 Related Issue

Closes #4

🛠 Changes Made

1. Setting a Monthly Budget (in index.html lines 40-42)
   There's a "Monthly Budget" input field and a "Set Budget" button on the home screen.

2. Budget persistence (in script.js )
   The budget value is saved to localStorage, so it persists even after you close the browser.

3. Two-level warnings (in script.js lines 183-193)
   🟠 Orange warning — "⚠ Approaching Monthly Budget (>= 80%)!" — appears when your filtered expenses reach 80% of the budget
   🔴 Red warning — "⚠ Monthly Budget Exceeded!" — appears when expenses exceed the budget
   These warnings show in the #budgetWarning div right below the total on the home screen.
   How to test it:
   Start your backend (node server.js from the backend/ folder)
   Open index.html in the browser Set a budget (e.g. ₹1000) Add expenses — when the total crosses ₹800, you'll see the orange warning. Past ₹1000, it turns red.Everything is in place — just make sure your backend server is running so the Add button works!

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✅ Checklist

• I have tested my changes
• My code follows project guidelines
• I have linked the related issue