feat: stages module, mobility frontend, theme toggle, employeeOnly access control

- Add stages module with full CRUD API and admin overview island
- Add mobility overview island (Liste, Kanban, Detail CRUD views)
- Add contract PDF upload/download endpoints for mobilites
- Add light/dark theme toggle in header
- Add employeeOnly flag to hide entire modules from students (admin, students, stages)
- Add read-only GET endpoints for modules/ues/ue-modules in notes module
- Add [slug].tsx catch-all routes for direct URL navigation
- Replace old mobility table with mobilites + stages schema (migration 0004)
- Allow students to create mobilites and upload contracts
- Redirect authenticated users from / to /apps catalog

routes/(apps)/notes/(_islands)/ImportNotes.tsx

@@ -273,9 +273,9 @@ export default function ImportNotes() {
     Promise.all([
       fetch("/students/api/students").then((r) => r.json()),
       fetch("/notes/api/notes").then((r) => r.json()),
-      fetch("/admin/api/modules").then((r) => r.json()),
-      fetch("/admin/api/ue-modules").then((r) => r.json()),
-      fetch("/admin/api/ues").then((r) => r.json()),
+      fetch("/notes/api/modules").then((r) => r.json()),
+      fetch("/notes/api/ue-modules").then((r) => r.json()),
+      fetch("/notes/api/ues").then((r) => r.json()),
     ]).then(
       ([
         studentsData,
@@ -450,7 +450,10 @@ export default function ImportNotes() {
         const ws2 = XLSX.utils.aoa_to_sheet([headerRow, coeffRow, ...s2Rows]);
         XLSX.utils.book_append_sheet(wb, ws2, "Session 2");
         const buf = XLSX.write(wb, { bookType: "xlsx", type: "array" });
-        const blob = new Blob([buf], { type: "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" });
+        const blob = new Blob([buf], {
+          type:
+            "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+        });
         const url = URL.createObjectURL(blob);
         const a = document.createElement("a");
         a.href = url;
@@ -600,6 +603,8 @@ export default function ImportNotes() {
         >
           Telecharger Modele
         </button>
+        {
+          /* TODO: fix blob download in Fresh
         <button
           type="button"
           class="btn btn-secondary"
@@ -607,6 +612,8 @@ export default function ImportNotes() {
         >
           Exporter Notes
         </button>
+        */
+        }
       </div>
 
       <p class="upload-format">