[jenbreese]

https://stanfordits.atlassian.net/browse/IFDM-339

Test Plan: Mortgage Refinancing Calculator v3 - Button Visibility Fix
Changes
Fixed the "See if it's worth it" button visibility so it remains visible while typing in new loan term fields. Previously, the button would disappear immediately when the user started entering data.

Test Steps

1. Initial page load

Navigate to the Mortgage Refinancing Calculator (v3)
Verify the "See if it's worth it" button is visible in the results panel on the right
2. Button persistence while typing

On the "Current Balance" tab, fill in:
Months remaining: 240
Current interest rate: 3.5
Monthly payment: $1,200
Click "Continue to refinance analysis" to go to the Refinance Analysis tab
Start typing in the "New loan amount" field (e.g., "300000")
Verify: The "See if it's worth it" button should still be visible (NOT disappear)
Continue typing in "New loan term" (e.g., "180")
Verify: Button remains visible
Type in "New interest rate" (e.g., "2.5")
Verify: Button still remains visible
3. Button click behavior

Click the "See if it's worth it" button
Verify: The button disappears and is replaced with the live results showing:
"Net value today" value
Refinancing verdict (green checkmark if worth it / red X if not)
Loan comparison table
Calculation breakdown section
4. Live results update (optional)

While results are displaying, change one of the values (e.g., adjust the interest rate)
Verify: Results update in real-time as you type
5. Reset behavior

Click "Reset new loan terms"
Verify: Values clear and the "See if it's worth it" button reappears (ready to be clicked again)
6. Tab switching

Go back to "Current Balance" tab, edit some values, return to "Refinance Analysis"
Verify: Button state resets appropriately

[majimmy88]

Tests work as expected, thanks Jen!

[majimmy88]

LGTM