Fix client autocomplete pagination + hide admin sidebar on front-end pages

fetchClientNames() requested page[limit]=200 but never followed
links.next, and JSON:API silently clamps to a 50-item hard cap -- with
106 client terms, everything past the 50th alphabetically (e.g. "LE
CAMPUS") was dropped. Now loops through every page like fetchLignes()
already does.

The core Navigation module's admin sidebar (#admin-toolbar) was showing
on our custom /lignes, /dashboard, /lignes/historique and lier-entree
pages. Added a route-scoped library (attached only for those route
names in hook_page_attachments(), not folded into the always-on
admin_chrome attachment) so real Drupal admin pages keep the sidebar.

web/modules/custom/figli_compta_ledger/css/hide-admin-sidebar.css

@@ -0,0 +1,13 @@
+/* The core Navigation module's admin sidebar (#admin-toolbar, ~65px fixed
+   rail) + its collapsed-state control bar and overlay. Only attached on
+   this module's own front-end routes (see
+   figli_compta_ledger_page_attachments()) -- real Drupal admin pages
+   (/admin/*, node edit forms, etc.) keep the sidebar as normal. */
+#admin-toolbar,
+.admin-toolbar-control-bar,
+.admin-toolbar-overlay {
+  display: none !important;
+}
+.dialog-off-canvas-main-canvas {
+  margin-inline-start: 0 !important;
+}