SOCFortress CoPilot: Hardcoded Default Header Secret - Unauthenticated Active-Response Invocation and Alert Injection

SOCFortress CoPilot focuses on providing a single pane of glass for all your security operations needs. Prior to 0.1.76, `verify_graylog_header` in `backend/app/active_response/routes/graylog.py` and `verify_velociraptor_header` in `backend/app/incidents/routes/incident_alert.py` authenticate webhooks against `GRAYLOG_API_HEADER_VALUE` and `VELOCIRAPTOR_API_HEADER_VALUE` with the same publicly hardcoded fallback. The same default is shipped in `.env.example`. Deployments that leave either setting unset or unchanged permit an anonymous caller with the known header value to bypass the JWT authentication required by normal APIs. `POST /api/graylog/invoke` forwards attacker-selected `COMMAND`, `ACTION`, `VALUE` and `AGENT_ID` to the configured Wazuh manager without the command-enum validation of the authenticated invocation route, allowing active-response scripts to disrupt endpoints and manipulate defensive controls. `POST /api/incidents/alerts/create/threshold` and `POST /api/incidents/alerts/create/velo-sigma` accept forged alerts for arbitrary `customer_code` values and drive attacker-controlled OpenSearch queries. Active-response delivery requires a configured reachable Wazuh manager. Deployments with independently changed header secrets are not subject to this default-secret bypass. This issue is fixed in version 0.1.76.