Add balancing entry to journal table to ensure debits equal credits

- Added getBalancingEntry method to calculate balancing entry
- Sums all debit amounts and subtracts all credit amounts
- If result < 0: adds debit to 4456700 account
- If result > 0: adds credit to 4456700 account
- Added parseAmount helper method to convert formatted amounts back to floats
- Journal table now automatically balances with calculated entry
- Ensures proper double-entry bookkeeping in OD journal

core/class/declarationtva_pdf.class.php

@@ -1862,6 +1862,12 @@ class DeclarationTVA_PDF
             $entries[] = $rounding_entry;
         }
         
+        // Add balancing entry to ensure debits equal credits
+        $balancing_entry = $this->getBalancingEntry($declaration, $entries);
+        if ($balancing_entry) {
+            $entries[] = $balancing_entry;
+        }
+        
         return $entries;
     }
     
@@ -2031,4 +2037,66 @@ class DeclarationTVA_PDF
         
         return $entry;
     }
+    
+    /**
+     * Get balancing entry to ensure debits equal credits
+     *
+     * @param DeclarationTVA $declaration Declaration object
+     * @param array $entries Current journal entries
+     * @return array|null Journal entry
+     */
+    private function getBalancingEntry($declaration, $entries)
+    {
+        $total_debits = 0;
+        $total_credits = 0;
+        
+        // Calculate totals from existing entries
+        foreach ($entries as $entry) {
+            if (!empty($entry['debit'])) {
+                $total_debits += $this->parseAmount($entry['debit']);
+            }
+            if (!empty($entry['credit'])) {
+                $total_credits += $this->parseAmount($entry['credit']);
+            }
+        }
+        
+        $difference = $total_debits - $total_credits;
+        
+        // If difference is very small (less than 0.01), no balancing entry needed
+        if (abs($difference) < 0.01) {
+            return null;
+        }
+        
+        $entry = array(
+            'account_code' => '4456700',
+            'account_label' => 'TVA à payer',
+            'entry_label' => $declaration->declaration_name,
+            'debit' => '',
+            'credit' => ''
+        );
+        
+        if ($difference < 0) {
+            // More credits than debits, add debit to balance
+            $entry['debit'] = $this->formatAmountReal(abs($difference));
+        } else {
+            // More debits than credits, add credit to balance
+            $entry['credit'] = $this->formatAmountReal($difference);
+        }
+        
+        return $entry;
+    }
+    
+    /**
+     * Parse amount string back to float
+     *
+     * @param string $amount_string Formatted amount string
+     * @return float Parsed amount
+     */
+    private function parseAmount($amount_string)
+    {
+        // Remove spaces and convert comma to dot
+        $amount_string = str_replace(' ', '', $amount_string);
+        $amount_string = str_replace(',', '.', $amount_string);
+        return (float)$amount_string;
+    }
 }