refactor: add migration, seed permissions, update permissions API

feat(notes): add XLSX import island and admin route

feat(upload): add drag‑and‑drop upload, template download, UI tweaks

routes/(apps)/notes/(_props)/props.ts

@@ -8,8 +8,9 @@ const properties: AppProperties = {
     notes: "Mes notes",
     courses: "Consulter",
     ues: "UEs",
+    import: "Import xlsx",
   },
-  adminOnly: ["courses", "ues"],
+  adminOnly: ["courses", "ues", "import"],
   hint: "Student grading management",
 };