Review fixes on top of #1578:
- Exiting Space Missions cancels the layer's own camera flights again (entry,
roster preview, mission focus); only a flight navigation started after
releaseCameraOwnership() runs on.
- A failed first index load says so: "Space Missions unavailable: the
mission index could not load. Try again later." on both the Context and
Data Layers routes, instead of a generic transition toast. Translated.
- Regression tests for both; docs and changelog describe the real feedback.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
