fix(agent): resolve config path absolutely and ensure correct CWD for background processes

fix(daemon): support nohup fallback for non-systemd Linux systems ...

- Detects if systemctl --user is functional.\n- Falls back to nohup background loop on NAS/OpenWRT.\n- Adds 'cortex-ctl' script for background management.

refactor: organize agent-node client code structure by moving core packages to src/ ...

- Moved agent_node, protos, and shared_core inside src/

- Updated Dockerfile, deployment scripts, compile_protos.sh, installers

- Updated bundle generation in ai-hub to reflect cleaner structure and better README

feat: add daemon/service installation for Mac and Linux ...

- Added install_service.py to configure launchd on macOS and systemd on Linux

- Added --daemon flag to bootstrap_installer.py which acts as a simple 1-click install