Make the ChicoryTV SPA the default UI: GET/HEAD requests to / and to
legacy Blazor routes with SPA equivalents (channels, schedules,
playouts, libraries, all settings pages, channel add) now 302 to their
/app counterparts, preserving query strings and the ETV_BASE_URL path
base. 302 not 301: the map will grow as parity lands and permanent-
redirect caching would make rollback painful.
Blazor-only functionality (collections, media browse/search, trakt,
filler presets, watermarks, ffmpeg profiles, blocks/decos/templates,
playout detail editors, logs, troubleshooting, channel edit) keeps
serving Blazor; the Blazor home stays reachable at /system/health.
Parity gaps are tracked in #140-#146; Blazor removal is phase (b).
Also adds an /app smoke assertion to the docker build workflow.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
