Clarify balancing entry account selection logic

- Debit balancing entries use 4456700 (TVA à payer)
- Credit balancing entries use 4455100 (TVA à recevoir)
- Account selection based on whether the balancing entry is debit or credit
- Proper French VAT accounting for balancing entries

core/class/declarationtva_pdf.class.php

@@ -2074,18 +2074,18 @@ class DeclarationTVA_PDF
         }
         
         if ($difference < 0) {
-            // More credits than debits, add debit to balance (TVA à payer)
+            // More credits than debits, add debit to balance
             $entry = array(
-                'account_code' => '4456700',
+                'account_code' => '4456700', // Debit entry uses 4456700
                 'account_label' => $this->getAccountLabel('4456700'),
                 'entry_label' => $declaration->declaration_name,
                 'debit' => $this->formatAmount(round(abs($difference))),
                 'credit' => ''
             );
         } else {
-            // More debits than credits, add credit to balance (TVA à recevoir)
+            // More debits than credits, add credit to balance
             $entry = array(
-                'account_code' => '4455100',
+                'account_code' => '4455100', // Credit entry uses 4455100
                 'account_label' => $this->getAccountLabel('4455100'),
                 'entry_label' => $declaration->declaration_name,
                 'debit' => '',