Replace the navigate-away ReleaseArchiveBrowser cards and the redundant top-level Releases
toggle with an in-page MudTabs strip under the Releases mode: ALL (CmsAllReleasesGrid) plus
one enum-driven tab per ReleaseMedium. Sessions/Mixes browsers gain an Embedded flag that
suppresses standalone page chrome when hosted as tab content; CmsCutBrowser is the new
Cut-filtered grid. /tracks/sessions, /tracks/mixes, /tracks/archive stay reachable by URL.
Session/Mix browsers share base (load/state/thumb) and a shared table shell carrying the per-row Edit link to BatchEdit; subclasses supply only their medium action.
Renames Genre tab to Release Archive with switch-free medium card group
(Enum.GetValues-driven). Adds MediumFields single dispatch + CutFields/SessionFields/
MixFields per-medium sections embedded by all five upload/edit forms. BatchUpload
enforces single-track invariant for Session/Mix. Adds CmsSessionBrowser (hero-image
upload) and CmsMixBrowser (waveform status + per-row Generate trigger).
ICmsReleaseService/CmsReleaseService wraps api/release endpoints.
Note: medium selector is forward-compat only — API write path pending.
daniel-c-harvey