Add solde totals footer row + fix JSON:API pagination duplicate bug

- tfoot row: sum per compte (créditeur/débiteur colored) for the
  currently filtered rows, plus HT/TTC/écart totals
- Fixed a real bug: fetchAllLignes() paginated without a unique sort key
  (field_date_ligne alone, many ties), which let Drupal's JSON:API return
  the same row on two pages -- silently inflating totals (Bachir showed
  -3115,38€ instead of -3013,56€). Now sorts by
  field_date_ligne,drupal_internal__nid (home) / drupal_internal__nid
  (dashboard), plus a defensive client-side de-dup by node id either way.

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

web/modules/custom/figli_compta_ledger/js/dashboard.js

@@ -11,7 +11,9 @@
   const EUR = new Intl.NumberFormat('fr-FR', { style: 'currency', currency: 'EUR' });
 
   async function fetchAllLignes() {
-    let url = API_BASE + '?include=field_repartition,field_repartition.field_compte,field_client&page[limit]=50';
+    // sort by nid: without an explicit, unique sort key, offset pagination
+    // can silently duplicate or skip rows across pages.
+    let url = API_BASE + '?include=field_repartition,field_repartition.field_compte,field_client&page[limit]=50&sort=drupal_internal__nid';
     const allData = [];
     const includedMap = new Map();
     while (url) {
@@ -22,7 +24,10 @@
       (json.included || []).forEach((item) => includedMap.set(item.type + ':' + item.id, item));
       url = json.links && json.links.next ? json.links.next.href : null;
     }
-    return { data: allData, includedMap };
+    // Defensive de-dup by node id, in case pagination ever repeats a row.
+    const seen = new Set();
+    const dedup = allData.filter((n) => (seen.has(n.id) ? false : (seen.add(n.id), true)));
+    return { data: dedup, includedMap };
   }
 
   function resolve(includedMap, ref) {