add some user delete functionalty

src/models/index.js

@@ -80,7 +80,7 @@ const Users = {
   },
 
   getAllUsers() {
-    return db.prepare('SELECT id, username, is_admin, is_organizer, created_at FROM users ORDER BY username ASC').all();
+    return db.prepare("SELECT id, username, is_admin, is_organizer, created_at FROM users WHERE username NOT LIKE '[deleted_%]' ORDER BY username ASC").all();
   },
 
   getTotalPoints(userId) {
@@ -136,6 +136,14 @@ const Users = {
 
   getTotalPlayerCount() {
     return db.prepare('SELECT COUNT(DISTINCT user_id) as count FROM scans WHERE points_awarded > 0').get().count;
+  },
+
+  deleteUser(userId) {
+    const placeholder = '[deleted_' + userId + ']';
+    db.prepare('UPDATE users SET username = ?, password_hash = ?, is_admin = 0, is_organizer = 0 WHERE id = ?')
+      .run(placeholder, '', userId);
+    db.prepare('UPDATE password_reset_tokens SET used = 1 WHERE user_id = ?').run(userId);
+    db.prepare("DELETE FROM sessions WHERE sess LIKE ?").run('%"userId":' + userId + '%');
   }
 };