Allow selecting several comptes/types at once in the filters

Compte and Type were single-value <select> elements. Converted both to
<select multiple> -- Vue binds those to an array natively, so
ctrl/cmd+click and shift+click just work with no custom JS. Matching
semantics are OR within a filter (any of the selected comptes/types) and
AND across filters, same as the existing client/year/écarts filters.

The URL hash (compte=Maud,Bachir&type=versement,achat) now carries
comma-separated lists instead of a single value, so the shareable/
reloadable filtered view still works with multiple selections.

web/modules/custom/figli_compta_ledger/css/home.css

@@ -58,6 +58,15 @@ html.gin--dark-mode #figli-home-app {
   border-radius: 4px;
 }
 
+/* Compte/Type filters: <select multiple> so ctrl/shift+click can select
+   several values, rendered as a short scrollable list (size="4") rather
+   than the single-line native default -- needs an explicit width, since
+   a multi-row select sizes to its widest option's natural width
+   otherwise, unlike a single-line select's fixed line box. */
+#figli-home-app .figli-toolbar select[multiple] {
+  width: 9rem;
+}
+
 #figli-home-app .figli-client-input {
   font-size: 0.85rem;
   padding: 0.2rem 0.4rem;