fix(migration): carry NOPAGO into transactions.outstanding

datosfreak's NOPAGO is the legacy "still owed" flag, and the website reads
it directly — account.statement.php splits the statement on NOPAGO = 0 vs
NOPAGO = 1 and renders the latter as "Outstanding Bills Requiring
Attention". transform_transactions.py hardcoded 0, so all 40,421 rows came
across settled and that section renders empty for anyone served off the
platform. Not a missing column: a missing section, with no error.

Only the three DATOS2-shaped tables carry the flag (76 rows set in datos2,
0 in FEE ANUAL and fee15); the EFECTIVO/FM3 cash streams have no such
column and keep the 0 default. Sync mode gets outstanding=VALUES(...) too,
so an additive sync corrects rows already loaded rather than leaving them
settled forever.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

migration/transform_transactions.py

@@ -149,10 +149,11 @@ def main():
     skip_cust = skip_date = skip_dupe = 0
 
     def add(cid, domain, tdate, amount, currency, *, period=None, reference=None,
-            typeid=None, check=None, message=None, src_db=None, src_tbl=None, legacy=None):
+            typeid=None, check=None, message=None, src_db=None, src_tbl=None, legacy=None,
+            outstanding=0):
         tx.append((str(uuid.uuid4()), cid, domain, typeid, tdate, period, reference,
                    amount if amount is not None else Decimal(0), currency, None, check,
-                   message, 0, src_db, src_tbl, legacy))
+                   message, outstanding, src_db, src_tbl, legacy))
 
     # Business key of a real cash payment. `folio` is deliberately excluded: it
     # is a per-table sequential number that collides between EFECTIVO and
@@ -230,6 +231,16 @@ def main():
                 src_db="UTILITIES", src_tbl=legacy_tbl, legacy=str(int(r["_row_num"])))
 
     def billing(name, legacy_tbl):
+        """Load a DATOS2-shaped billing ledger.
+
+        NOPAGO is the legacy "still owed" flag. The website reads it directly —
+        `account.statement.php` splits the statement on `NOPAGO = 0` vs
+        `NOPAGO = 1` and renders the latter as the "Outstanding Bills Requiring
+        Attention" table — so dropping it does not merely lose a column, it
+        silently empties that whole section for anyone served off the platform.
+        Only these three tables carry it (76 rows set in DATOS2 today); the
+        EFECTIVO/FM3 cash streams have no such column and stay 0.
+        """
         nonlocal skip_cust, skip_date
         df = load("stg_utilities", name)
         for _, r in df.iterrows():
@@ -243,7 +254,8 @@ def main():
             add(cid, "UTILITY", td, dec(r["chargecredit"], Decimal(0)), "MXN",
                 period=s(r["period"]), reference=s(r["refer"]), typeid=tid,
                 check=s(r["cheque"]), src_db="UTILITIES", src_tbl=legacy_tbl,
-                legacy=str(int(r["_row_num"])))
+                legacy=str(int(r["_row_num"])),
+                outstanding=1 if s(r["nopago"]) == "1" else 0)
 
     def iva():
         nonlocal skip_cust
@@ -297,7 +309,7 @@ def main():
         if new_types:
             c.executemany("INSERT INTO type_transactions (id,nameEn,nameEs,isService) VALUES (%s,%s,%s,%s)", new_types)
         tx = [(t[0], t[1], t[2], (db_types.get(fresh_name.get(t[3])) if t[3] else None), *t[4:]) for t in tx]
-        c.executemany("INSERT INTO transactions (id,customerId,domain,typeId,transactionDate,period,reference,amount,currency,exchangeRate,checkNumber,message,outstanding,legacySourceDb,legacySourceTable,legacyId) VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s) ON DUPLICATE KEY UPDATE customerId=VALUES(customerId),domain=VALUES(domain),typeId=VALUES(typeId),transactionDate=VALUES(transactionDate),period=VALUES(period),reference=VALUES(reference),amount=VALUES(amount),currency=VALUES(currency),checkNumber=VALUES(checkNumber),message=VALUES(message),voidedAt=NULL", tx)
+        c.executemany("INSERT INTO transactions (id,customerId,domain,typeId,transactionDate,period,reference,amount,currency,exchangeRate,checkNumber,message,outstanding,legacySourceDb,legacySourceTable,legacyId) VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s) ON DUPLICATE KEY UPDATE customerId=VALUES(customerId),domain=VALUES(domain),typeId=VALUES(typeId),transactionDate=VALUES(transactionDate),period=VALUES(period),reference=VALUES(reference),amount=VALUES(amount),currency=VALUES(currency),checkNumber=VALUES(checkNumber),message=VALUES(message),outstanding=VALUES(outstanding),voidedAt=NULL", tx)
     else:
         c.execute("SET FOREIGN_KEY_CHECKS=0")
         for t in ("transactions", "type_transactions", "exchange_rates"):