Fix Cesium simulation map loading and interactions

[BohanZhang1]

Summary

• inject the local Cesium Ion token through Vite's supported \import.meta.env\ replacement
• load Cesium asset 2275207 asynchronously and show a visible error when the tileset cannot resolve or render
• use the configured origin for the initial camera, with Chicago O'Hare as the fallback for unset coordinates
• keep Cesium camera rotation and tilt enabled during mission configuration, including middle-button drag handling
• synchronize map-based drone placement directly into the shared mission model so Home latitude and longitude update immediately
• remove the duplicated mission drone state that could diverge from the submitted DRV configuration

DRV scope

This ports only frontend interaction behavior needed by DRV. SADE-specific authentication, software-pilot, calibration, coverage, and case-study features are intentionally excluded. The Cesium credential file is also excluded from this PR.

Validation

• \docker compose -p droneworld -f docker-compose.dev.yaml exec -T frontend npx eslint src\
• \docker compose -p droneworld -f docker-compose.dev.yaml exec -T frontend npm run build\
• verified \http://localhost:3000/simulation\ responds with HTTP 200 from the live frontend container
• verified frontend, backend, and fake GCS containers are running, with fake GCS healthy

Manual review checklist

• confirm Google Photorealistic 3D Tiles asset 2275207 loads with a locally configured token
• middle-button drag rotates or tilts the camera on the Mission step
• dragging a drone onto the map updates its Home latitude and longitude fields
• changing Home coordinates and navigating between configuration steps preserves the submitted values