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/index.tsx

@@ -1,13 +1,28 @@
-import { FreshContext } from "$fresh/server.ts";
+import { FreshContext, Handlers } from "$fresh/server.ts";
+import { State } from "$root/defaults/interfaces.ts";
 
-// deno-lint-ignore require-await
-export default async function Home(_request: Request, _context: FreshContext) {
+export const handler: Handlers<unknown, State> = {
+  GET(_request: Request, context: FreshContext<State>) {
+    if (context.state.isAuthenticated) {
+      return new Response(null, {
+        status: 302,
+        headers: { Location: "/apps" },
+      });
+    }
+    return context.render();
+  },
+};
+
+export default function Home() {
   return (
     <>
       <h2>PolyMPR</h2>
       <h3>
         The <em>ultimate</em> HR platform
       </h3>
+      <p>
+        <a href="/login">Se connecter</a>
+      </p>
     </>
   );
 }