chore: enhance demo script and update dependencies for improved compa…

[stash-labs]

Changes Summary - Quick Reference

⚠️ Breaking Issues Fixed

Issue	Before	After
Bash Version	Script crashed on macOS (Bash 3.2)	Added version check + install guide
Netcat Command	netcat not found on macOS	Changed to nc (universal)
Stat Command	stat -c %u (Linux only)	stat -f %u with fallback
Wallet Descriptor	Missing fingerprint	Full descriptor with origin
Wallet Naming	wallet_0/ directory	wallet_0.wallet/ directory
Sync Command	Panic: mempool argument error	Uses fixed branch HEAD
YAML Format	api: rLosfg	checksum: AYkSrg
Codex ID	Wrong ID (unknown codex error)	Correct ID from issuer file
Pay Command	Missing indexer parameter	Added $INDEXER_CLI
Docker Health	Services race condition	Added health checks

✅ Test Results

Before: ❌ Script failed at multiple points
- Bash version error
- Wallet descriptor error  
- Wallet not found error
- Sync command panic
- Unknown codex error
- Missing indexer error

After: ✅ Complete success
╔════════════════════════════════════════╗
║   sandbox run finished                 ║
║   • 2 contracts issued                 ║
║   • 11 transfers completed             ║
║   • All balances verified              ║
╚════════════════════════════════════════╝