Add one-command install script and stability fixes

- Add install.sh for automated setup
- Add all component files (wrapper, service, config, verify)
- Add stability fixes section (WiFi PowerSave disable + Watchdog)
- Update README with new installation instructions

verify.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+echo "🔍 USB Audio Check:"
+arecord -l | grep "card 0" || echo "⚠️  No card 0 found"
+
+echo -e "\n📊 Service Status:"
+systemctl status sonos-aux.service --no-pager || echo "⚠️  Service not running"
+
+echo -e "\n📜 Last 20 log lines:"
+journalctl -u sonos-aux.service -n20 --no-pager || echo "⚠️  No logs found"
+
+echo -e "\n🌐 Icecast streams:"
+curl -s http://localhost:8000/status-json.xsl 2>/dev/null | grep -o 'http[^<]*' || echo "⚠️  Icecast not responding"