fix: expose Hermes API settings to Docker

[RayStudents]

Summary

• forward VO_HERMES_API_URL into the Virtual Office container
• forward VO_HERMES_API_KEY for authenticated Hermes API requests
• default both optional values to empty strings when unset

Verification

• ad-hoc Docker Compose render check confirmed configured Hermes API values are forwarded
• ad-hoc Docker Compose render check confirmed unset values safely render as empty strings
• docker compose config --quiet passed

No canonical project test suite was detected for this Compose-only change.