- _portal_device_id() reads from session, falls back to DEVICE_NAME env var
- GET/POST /api/v1/portal/select-device for selector data + set
- Dropdown in server base.html topbar, JS populates from API, page reloads on change
- All portal pages (overview, trips, dashcam, DTC, device settings) now use selected device
- DashcamScreen: LazyColumn of imported Pi videos with thumbnails (Coil),
file size, date, upload status, converting progress
- DashcamViewModel: Retrofit-backed video list + download to phone storage
+ delete local copy
- PiApi extended: listVideos, getVideoFile (streaming), getThumbnail, deleteVideo
- DTOs: VideoListResponse, VideoFile, ConvertProgress
- Bottom nav: Dashcam tab + Test tab
- Verified: video list loads from real Pi over yaris 911 hotspot