Docker dashboard insecure binding now requires explicit HERMES_DASHBOARD_INSECURE=1 opt-in

What this changes for operators

• The dashboard no longer infers insecure mode from bind host, so operators whose Docker setups relied on that inference must add HERMES_DASHBOARD_INSECURE=1 explicitly or the dashboard will not bind insecurely.
• Existing Docker and hosted deployments must update env configuration before upgrading to v0.15.1 to avoid a broken or unexpectedly-secured dashboard.
• Verification path: upgrade to v0.15.1, set HERMES_DASHBOARD_INSECURE=1 only where intended, and confirm the dashboard binds as expected without falling back to host-derived inference.