[Feature] Budget Object: Add Fields for Paycheck Budgeting

As a user, I want to track paycheck-level budgeting by adding key fields like total income, total expenses, and remaining income, so I can monitor how much I have left after fixed costs.

Acceptance Criteria

1. Add Total Income Field (currency)
2. Add Total Fixed Expenses Field (formula?)
3. Add Remaining Income Field ( formula Total Income - Total Fixed Expenses)
4. Add Pay Check Date Field (Date)
5. Add Month Field (Picklist)
6. Add Field Notes (optional text area)
7. All fields for a budget record are viewable on budget tab

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Issue metadata

• Issue type: Story
• Priority: Medium
• Parent issue: [JDTDEV-45] Personal Salesforce Budget App
• Fix versions: Salesforce Budget App v1.0