feat: add social features, leaderboard, auth enhancements, and admin fixes

- Implement Social Features: Shared Tasks, Global Access, Privacy Settings (Leaderboard/Searchable).
- Add Leaderboard Page and API.
- Enhance Auth: Support Email/Username login, explicit duplicate registration errors.
- Fix: Admin login password hash regression.
- Refactor: Move to wouter for routing, add Admin Dashboard and User Management.
- Add Setup Wizard.
- Update UI with Sidebar and Gamification elements.

migration.sql

@@ -0,0 +1,23 @@
+-- Create system_settings table
+CREATE TABLE IF NOT EXISTS system_settings (
+    id varchar(255) PRIMARY KEY DEFAULT gen_random_uuid(),
+    key text NOT NULL UNIQUE,
+    value text NOT NULL,
+    updated_at timestamp DEFAULT now()
+);
+
+-- Truncate users to avoid constraint issues and reset for First Run
+TRUNCATE TABLE users CASCADE;
+TRUNCATE TABLE user_rewards CASCADE;
+TRUNCATE TABLE xp_events CASCADE;
+TRUNCATE TABLE goals CASCADE;
+TRUNCATE TABLE notes CASCADE;
+
+-- Add new columns to users
+ALTER TABLE users ADD COLUMN IF NOT EXISTS email text NOT NULL UNIQUE;
+ALTER TABLE users ADD COLUMN IF NOT EXISTS role text NOT NULL DEFAULT 'user';
+ALTER TABLE users ADD COLUMN IF NOT EXISTS is_active boolean NOT NULL DEFAULT true;
+
+-- Verification
+SELECT count(*) FROM system_settings;
+SELECT count(*) FROM users;