Add getAccountMappings() method to retrieve account labels

Fixed:
- Added missing getAccountMappings() method to DeclarationTVA class
- Joins with Dolibarr's accounting_account table to get labels
- Retrieves account labels from chart of accounts (llx_accounting_account)
- Falls back to stored label if chart of accounts label not available
- Returns array with rowid, ca3_line, account_code, account_label, vat_rate, is_active

This fixes the issue where account labels were not showing in dropdown panels.

core/class/declarationtva.class.php

@@ -856,6 +856,42 @@ class DeclarationTVA
         return $this->calculateCA3Amounts($declaration_id, $period);
     }
 
+    /**
+     * Get account mappings with labels from chart of accounts
+     *
+     * @return array Array of account mappings with labels
+     */
+    public function getAccountMappings()
+    {
+        $sql = "SELECT m.rowid, m.ca3_line, m.account_code, m.account_label, m.vat_rate, m.is_active,
+                       a.label as account_label_pcg
+                FROM " . MAIN_DB_PREFIX . "declarationtva_account_mappings m
+                LEFT JOIN " . MAIN_DB_PREFIX . "accounting_account a ON a.account_number = m.account_code AND a.entity = m.entity
+                WHERE m.entity = " . $this->entity . " AND m.is_active = 1
+                ORDER BY m.ca3_line, m.account_code";
+        
+        $result = $this->db->query($sql);
+        $mappings = array();
+        
+        if ($result) {
+            while ($obj = $this->db->fetch_object($result)) {
+                // Use the label from chart of accounts if available, otherwise use the stored label
+                $account_label = !empty($obj->account_label_pcg) ? $obj->account_label_pcg : $obj->account_label;
+                
+                $mappings[] = array(
+                    'rowid' => $obj->rowid,
+                    'ca3_line' => $obj->ca3_line,
+                    'account_code' => $obj->account_code,
+                    'account_label' => $account_label,
+                    'vat_rate' => $obj->vat_rate,
+                    'is_active' => $obj->is_active
+                );
+            }
+        }
+        
+        return $mappings;
+    }
+
     /**
      * Get detailed account breakdown for a specific CA-3 line
      *