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.

client/src/lib/sounds.ts

@@ -0,0 +1,31 @@
+// Simple sound effects using base64 or public URLs to avoid asset management issues for this demo
+// Using a short "pop" sound
+
+const POP_SOUND = "data:audio/wav;base64,UklGRl9vT19XQVZFZm10IBAAAAABAAEAQB8AAEAfAAABAAgAZGF0YU"; // Placeholder, real sound below
+
+export const playSuccessSound = () => {
+    // A simple pleasant "pop" sound frequency sequence using Web Audio API for zero-dependency
+    try {
+        const AudioContext = window.AudioContext || (window as any).webkitAudioContext;
+        if (!AudioContext) return;
+
+        const ctx = new AudioContext();
+        const osc = ctx.createOscillator();
+        const gain = ctx.createGain();
+
+        osc.connect(gain);
+        gain.connect(ctx.destination);
+
+        osc.type = 'sine';
+        osc.frequency.setValueAtTime(800, ctx.currentTime);
+        osc.frequency.exponentialRampToValueAtTime(1200, ctx.currentTime + 0.1);
+
+        gain.gain.setValueAtTime(0.3, ctx.currentTime);
+        gain.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 0.1);
+
+        osc.start(ctx.currentTime);
+        osc.stop(ctx.currentTime + 0.1);
+    } catch (e) {
+        console.error("Audio play failed", e);
+    }
+};