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)/students/partials/(admin)/upload.tsx

@@ -9,10 +9,16 @@ import { State } from "$root/defaults/interfaces.ts";
 // deno-lint-ignore require-await
 async function Students(_request: Request, _context: FreshContext<State>) {
   return (
-    <>
-      <h2>Upload Students</h2>
+    <div class="page-content">
+      <h2 class="page-title">Importer des Élèves</h2>
+      <p
+        class="upload-format"
+        style="margin-bottom: 1.25rem"
+      >
+        POST /students/api/students/import-csv
+      </p>
       <UploadStudents />
-    </>
+    </div>
   );
 }