feat: wire systemd services to use centralized aitbc package

- Create wrapper scripts for all AITBC services using aitbc utilities
- Update 13 systemd service files to use wrapper scripts
- Wrapper scripts use aitbc constants (ENV_FILE, NODE_ENV_FILE, DATA_DIR, LOG_DIR, KEYSTORE_DIR)
- Services migrated: agent-coordinator, agent-daemon, agent-registry, blockchain-event-bridge, blockchain-node, blockchain-p2p, blockchain-rpc, blockchain-sync, coordinator-api, explorer, marketplace, wallet
- Add sys.path setup to cli/aitbc_cli.py for aitbc package access
- Centralized path management via aitbc package
- Consistent environment setup across all services

systemd/aitbc-explorer.service

@@ -5,12 +5,11 @@ After=network.target aitbc-blockchain-rpc-1.service aitbc-blockchain-rpc-2.servi
 [Service]
 Type=simple
 User=root
-WorkingDirectory=/opt/aitbc/apps/blockchain-explorer
-# Using the blockchain node venv since the coordinator one is broken
+WorkingDirectory=/opt/aitbc
 Environment=PATH=/usr/bin:/usr/local/bin:/usr/bin:/bin
 EnvironmentFile=/etc/aitbc/.env
 EnvironmentFile=/etc/aitbc/node.env
-ExecStart=/opt/aitbc/venv/bin/python main.py
+ExecStart=/opt/aitbc/venv/bin/python /opt/aitbc/scripts/wrappers/aitbc-explorer-wrapper.py
 Restart=always
 RestartSec=5
 StandardOutput=journal