Add registration page, fix auth paths, and improve navigation

scripts/hash-password.js

@@ -0,0 +1,14 @@
+import bcrypt from 'bcryptjs'
+
+const password = process.argv[2] || 'admin123'
+
+bcrypt.hash(password, 10, (err, hash) => {
+  if (err) {
+    console.error('Fehler:', err)
+    return
+  }
+  console.log('\nPasswort:', password)
+  console.log('Hash:', hash)
+  console.log('\nKopieren Sie diesen Hash in server/data/users.json\n')
+})
+