## Summary
- **Bug**: The `loans:generate-balances` command called
`getBalanceAtDate()` which always recalculated the remaining balance
from the **original loan parameters** (`original_amount`,
`annual_interest_rate`, `loan_term_months`, `start_date`), completely
ignoring existing actual balance entries. When the real balance was
lower than the theoretical amortization schedule (e.g. user made extra
payments), the auto-generated balance would **jump up** instead of
continuing to decrease.
- **Example**: Account `019d0b33-d3c5-7110-9033-51155ac93219` had a real
balance of ~4,489,670 (March 2026), but the command generated 5,700,356
(April 2026) — a jump **up** of ~1.2M cents instead of the expected ~16K
decrease.
- **Fix**: `getBalanceAtDate()` now checks for the latest
`AccountBalance` entry on or before the target date and projects forward
from it, falling back to the theoretical formula only when no entries
exist. This matches the method's own documented behavior and aligns with
how `generateProjection()` already works.
## Testing
Added 4 new tests:
- Projects from existing balance entries instead of original loan params
- Returns existing balance when target date is in the same month
- Generates correct monthly balance when existing entries differ from
theoretical
- All 44 existing loan tests continue to pass
7e958284e3