fix(ledger): preserve exact decimal amount in manual and unified responses

Co-authored-by: genichin <4282227+genichin@users.noreply.github.com>

app/repositories/postgres.py

@@ -711,6 +711,7 @@ class PostgresPortfolioRepository:
             side=row[2],
             quantity=float(row[4]),
             price=float(row[3]),
+            price_decimal=Decimal(str(row[3])) if row[3] is not None else None,
             fee_amount=float(row[5]),
             tax_amount=float(row[6]),
             executed_at=row[1],
@@ -1864,6 +1865,7 @@ class PostgresPortfolioRepository:
     def _row_to_ledger_entry(row: Any) -> LedgerEntry:
         if row is None:
             raise ValueError("원장 항목을 찾을 수 없습니다")
+        raw_price = row[6]
         return LedgerEntry(
             ledger_entry_id=int(row[0]),
             portfolio_id=row[1],
@@ -1871,7 +1873,8 @@ class PostgresPortfolioRepository:
             execution_id=row[3],
             side=row[4],
             quantity=float(row[5]),
-            price=float(row[6]),
+            price=float(raw_price),
+            price_decimal=Decimal(str(raw_price)) if raw_price is not None else None,
             fee_amount=float(row[7]),
             tax_amount=float(row[8]),
             executed_at=row[9],