Add solde footer to the "Lignes signalées" table on /dashboard/compte

Sum of the Montant column across every flagged line for the selected
compte, styled red when negative -- same convention as the other
reconciliation tables' footers on this page.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/modules/custom/figli_compta_ledger/templates/figli-compta-dashboard-compte.html.twig

@@ -123,6 +123,12 @@
             <td :class="r.parCompte[selectedCompte] < 0 ? 'is-negative' : ''">{{ formatEur(r.parCompte[selectedCompte]) }}</td>
           </tr>
         </tbody>
+        <tfoot>
+          <tr>
+            <td colspan="5">Solde</td>
+            <td :class="totalLignesSignalees < 0 ? 'is-negative' : ''">{{ formatEur(totalLignesSignalees) }}</td>
+          </tr>
+        </tfoot>
       </table>
     </section>