initial: Ethica Agent v0.1.0

Lightweight telemetry agent (stdlib-only, Python 3.8+) that collects
metrics via pre-defined widget types and pushes to POST /api/company/metrics.

Widget types: system_cpu, system_memory, system_disk, http_check,
              port_check, process_check, custom_cmd

Platform: Linux (fully). Windows collectors stubbed (NOT_IMPL markers)
ready for porting without changing call sites. system_disk / http_check /
port_check / custom_cmd already cross-platform.

Delivery: run directly (python3 ethica-agent.py --config ethica-agent.yml),
as a systemd service (ethica-agent.service), or as a Docker container.

ethica-agent.service

@@ -0,0 +1,15 @@
+[Unit]
+Description=Ethica Agent
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+ExecStart=/usr/bin/python3 /opt/ethica-agent/ethica-agent.py --config /opt/ethica-agent/ethica-agent.yml
+Restart=always
+RestartSec=15
+StandardOutput=journal
+StandardError=journal
+
+[Install]
+WantedBy=multi-user.target