fix: Update Trial Balance to use real VBAL VIEW structure

After database verification, VBAL is a VIEW (not a table) that exists
in each company schema with a different structure than initially assumed.

Backend Changes:
- Updated models (trial_balance.py):
  - Changed column names to match real VBAL VIEW
  - CONT (account number)
  - DENUMIRE (account description, not DCONT)
  - PRECDEB/PRECCRED (previous balance, not SD_PREC/SC_PREC)
  - RULDEB/RULCRED (monthly movement, not RD_LUNA/RC_LUNA)
  - SOLDDEB/SOLDCRED (final balance, not SD_FINAL/SC_FINAL)
  - Made DENUMIRE optional (can be NULL in VIEW)

- Updated router (trial_balance.py):
  - Removed COD_FIRMA filter (not in VIEW)
  - Query now uses: {schema}.VBAL WHERE AN = :an AND LUNA = :luna
  - Fixed column names in SELECT (DENUMIRE instead of DCONT)
  - Updated sort columns validation
  - Fixed result processing to match new column order

Frontend Changes:
- Updated TrialBalanceView.vue:
  - Changed field from 'dcont' to 'denumire' in DataTable column

Database Verification:
- VBAL VIEW confirmed in ROMFAST schema (24,217 records)
- Current data available up to November 2025
- Structure verified with 22 columns
- VIEW exists in all company schemas

Testing Notes:
- Backend endpoint ready for testing
- Frontend field names now match API response
- Ready for manual testing with real company data

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

reports-app/backend/app/routers/trial_balance.py

@@ -64,8 +64,9 @@ async def get_trial_balance(
             sort_order = 'asc'
 
         # Validează sort_by (previne SQL injection)
-        valid_sort_columns = ['CONT', 'DCONT', 'SD_PREC', 'SC_PREC', 'RD_LUNA',
-                             'RC_LUNA', 'SD_FINAL', 'SC_FINAL']
+        # Real column names from VBAL VIEW
+        valid_sort_columns = ['CONT', 'DENUMIRE', 'PRECDEB', 'PRECCRED',
+                             'RULDEB', 'RULCRED', 'SOLDDEB', 'SOLDCRED']
         if sort_by.upper() not in valid_sort_columns:
             sort_by = 'CONT'
 
@@ -90,25 +91,25 @@ async def get_trial_balance(
 
                 schema = schema_result[0]
 
-                # Construiește query-ul de bază pentru VBAL
+                # Construiește query-ul de bază pentru VBAL VIEW
+                # VBAL este un VIEW în fiecare schemă de companie
+                # Structura reală: CONT, DENUMIRE, AN, LUNA, PRECDEB, PRECCRED, RULDEB, RULCRED, SOLDDEB, SOLDCRED
                 base_query = f"""
                     SELECT
                         CONT,
-                        DCONT,
-                        NVL(SD_PREC, 0) as SD_PREC,
-                        NVL(SC_PREC, 0) as SC_PREC,
-                        NVL(RD_LUNA, 0) as RD_LUNA,
-                        NVL(RC_LUNA, 0) as RC_LUNA,
-                        NVL(SD_FINAL, 0) as SD_FINAL,
-                        NVL(SC_FINAL, 0) as SC_FINAL
+                        NVL(DENUMIRE, '') as DENUMIRE,
+                        NVL(PRECDEB, 0) as PRECDEB,
+                        NVL(PRECCRED, 0) as PRECCRED,
+                        NVL(RULDEB, 0) as RULDEB,
+                        NVL(RULCRED, 0) as RULCRED,
+                        NVL(SOLDDEB, 0) as SOLDDEB,
+                        NVL(SOLDCRED, 0) as SOLDCRED
                     FROM {schema}.VBAL
-                    WHERE COD_FIRMA = :cod_firma
-                      AND AN = :an
+                    WHERE AN = :an
                       AND LUNA = :luna
                 """
 
                 params = {
-                    'cod_firma': company,
                     'an': an,
                     'luna': luna
                 }
@@ -119,7 +120,7 @@ async def get_trial_balance(
                     params['cont_filter'] = f"{cont_filter}%"
 
                 if denumire_filter:
-                    base_query += " AND UPPER(DCONT) LIKE UPPER(:denumire_filter)"
+                    base_query += " AND UPPER(DENUMIRE) LIKE UPPER(:denumire_filter)"
                     params['denumire_filter'] = f"%{denumire_filter}%"
 
                 # Count total pentru paginare
@@ -148,11 +149,13 @@ async def get_trial_balance(
                 rows = cursor.fetchall()
 
                 # Procesează rezultatele
+                # Index columns: CONT(0), DENUMIRE(1), PRECDEB(2), PRECCRED(3),
+                #                RULDEB(4), RULCRED(5), SOLDDEB(6), SOLDCRED(7), rnum(8)
                 items = []
                 for row in rows:
                     item = TrialBalanceItem(
                         cont=row[0] or '',
-                        dcont=row[1] or '',
+                        denumire=row[1] or '',
                         sold_precedent_debit=Decimal(str(row[2] or 0)),
                         sold_precedent_credit=Decimal(str(row[3] or 0)),
                         rulaj_lunar_debit=Decimal(str(row[4] or 0)),