Adds a "Dev Disable-Login Flag" subsection to Component-Security.md covering
ScadaBridge:Security:Auth:DisableLogin / User, the AutoLoginAuthenticationHandler
mechanism, and the no-environment-guard / startup-warning production risk.
Ships DisableLogin: false under ScadaBridge → Security → Auth in:
- src/.../Host/appsettings.json (canonical default)
- docker/central-node-a/appsettings.Central.json
- docker/central-node-b/appsettings.Central.json
Also records DL-3 commit SHAs in the plan tasks file.