ZEVA 2 - No credit values shown for suppliers in deficit in ZEV Unit Transactions tab

**Describe the Bug**
When a supplier is listed in deficit, no credit values are displayed in the "Current Balance" section at the top of the "ZEV Unit Transactions" tab. However, when suppliers are not in deficit, a year-by-year credit balance summary is shown. This creates an inconsistent experience and makes it difficult to assess the historical credit balance for suppliers in deficit.

**Expected Behaviour**
The credit values in the "Current Balance" section should be displayed for suppliers even when they are in deficit, mirroring the presentation for suppliers not in deficit. This ensures year-by-year clarity regardless of supplier status.

**Actual Behaviour**
When the supplier is in deficit, the credit values are not shown; when the supplier is not in deficit, a year-by-year balance is visible at the top of the tab.

**Implications**
This issue can confuse users and make it challenging to track credit history for suppliers who are currently in deficit. It reduces the transparency and consistency of information presentation in the ZEV Unit Transactions interface.

**Steps To Reproduce**
User/Role: BCeID Tester or Analyst
1. Go to the ZEV Unit Transactions tab for any supplier record. (dFord is currently in Deficit)
2. Confirm the supplier is in deficit status.
3. Observe the "Current Balance" section at the top.
4. Note that the credit values are not shown.
5. Change to or view a supplier not in deficit; observe that credit values and year-by-year balance are displayed.

Start in the frontend entry point for the ZEV Unit Transactions tab and reproduce the comparison using a deficit supplier such as dFord and a supplier not in deficit. Trace how the Current Balance section receives its year-by-year credit values; done means the same credit history is displayed for suppliers in deficit and those not in deficit.

Written by the indexing model from the issue text.