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/models/trial_balance.py

@@ -1,6 +1,6 @@
 """
 Pydantic models for Trial Balance (Balanță de Verificare)
-Maps to Oracle VBAL table
+Maps to Oracle VBAL VIEW (exists in each company schema)
 """
 from pydantic import BaseModel, Field
 from typing import Optional, List
@@ -8,16 +8,22 @@ from decimal import Decimal
 
 class TrialBalanceItem(BaseModel):
     """
-    Individual trial balance record from VBAL table
+    Individual trial balance record from VBAL VIEW
+    Real structure from Oracle:
+    - CONT: account number
+    - DENUMIRE: account description
+    - PRECDEB/PRECCRED: previous balance debit/credit
+    - RULDEB/RULCRED: monthly movement debit/credit
+    - SOLDDEB/SOLDCRED: final balance debit/credit
     """
-    cont: str = Field(description="Număr cont contabil")
-    dcont: str = Field(description="Denumire cont")
-    sold_precedent_debit: Decimal = Field(description="Sold precedent debit", decimal_places=2)
-    sold_precedent_credit: Decimal = Field(description="Sold precedent credit", decimal_places=2)
-    rulaj_lunar_debit: Decimal = Field(description="Rulaj lunar debit", decimal_places=2)
-    rulaj_lunar_credit: Decimal = Field(description="Rulaj lunar credit", decimal_places=2)
-    sold_final_debit: Decimal = Field(description="Sold final debit", decimal_places=2)
-    sold_final_credit: Decimal = Field(description="Sold final credit", decimal_places=2)
+    cont: str = Field(description="Număr cont contabil (CONT)")
+    denumire: Optional[str] = Field(default="", description="Denumire cont (DENUMIRE)")
+    sold_precedent_debit: Decimal = Field(description="Sold precedent debit (PRECDEB)", decimal_places=2)
+    sold_precedent_credit: Decimal = Field(description="Sold precedent credit (PRECCRED)", decimal_places=2)
+    rulaj_lunar_debit: Decimal = Field(description="Rulaj lunar debit (RULDEB)", decimal_places=2)
+    rulaj_lunar_credit: Decimal = Field(description="Rulaj lunar credit (RULCRED)", decimal_places=2)
+    sold_final_debit: Decimal = Field(description="Sold final debit (SOLDDEB)", decimal_places=2)
+    sold_final_credit: Decimal = Field(description="Sold final credit (SOLDCRED)", decimal_places=2)
 
     class Config:
         from_attributes = True