refactor: convert aitbc-cli to symlink and enhance CLI command structure

CLI Wrapper Changes:
- Converted aitbc-cli from bash wrapper script to direct symlink
- Symlink points to python3 /opt/aitbc/cli/aitbc_cli.py
- Simplified CLI invocation and removed wrapper overhead

CLI Command Enhancements:
- Added system status command with version and service info
- Added blockchain subcommands (info, height, block)
- Added wallet subcommands (backup, export, sync, balance)
- Added network subcommands (status

scripts/training/training_lib.sh

@@ -11,7 +11,7 @@
 # ============================================================================
 
 # Default configuration (can be overridden)
-export CLI_PATH="${CLI_PATH:-/opt/aitbc/aitbc-cli}"
+export CLI_PATH="${CLI_PATH:-python3 /opt/aitbc/cli/aitbc_cli.py}"
 export LOG_DIR="${LOG_DIR:-/var/log/aitbc}"
 export WALLET_NAME="${WALLET_NAME:-openclaw-trainee}"
 export WALLET_PASSWORD="${WALLET_PASSWORD:-trainee123}"