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-blockchain-rpc.service

@@ -6,13 +6,12 @@ After=network.target aitbc-blockchain-node.service
 Type=simple
 User=root
 Group=root
-WorkingDirectory=/opt/aitbc/apps/blockchain-node
+WorkingDirectory=/opt/aitbc
+Environment=PATH=/usr/bin:/usr/local/bin:/usr/bin:/bin
 EnvironmentFile=/etc/aitbc/.env
 EnvironmentFile=/etc/aitbc/node.env
-Environment=PATH=/usr/bin:/usr/local/bin:/usr/bin:/bin
-Environment=PYTHONPATH=/opt/aitbc/apps/blockchain-node/src:/opt/aitbc/apps/blockchain-node/scripts
 UnsetEnvironment=enable_block_production ENABLE_BLOCK_PRODUCTION
-ExecStart=/usr/bin/env enable_block_production=false /opt/aitbc/venv/bin/python -m uvicorn aitbc_chain.app:app --host ${rpc_bind_host} --port ${rpc_bind_port}
+ExecStart=/opt/aitbc/venv/bin/python /opt/aitbc/scripts/wrappers/aitbc-blockchain-rpc-wrapper.py
 Restart=always
 RestartSec=5
 StandardOutput=journal