docs: archive track detail page to COMPLETED.md; update CLAUDE.md

DeepDrftPublic.Client/CLAUDE.md

@@ -10,7 +10,7 @@ All interactive UI for the site. Blazor WebAssembly. Pages, controls, the stream
 
 ## Actual structure
 
-- `Pages/`: Routable components. `Home.razor` (hero/about), `TracksView.razor` (track gallery with pagination/sorting). **No demo pages** (`Counter.razor`, `Weather.razor` do not exist).
+- `Pages/`: Routable components. `Home.razor` (hero/about), `TracksView.razor` (track gallery with pagination/sorting), `TrackDetail.razor` (single-track detail view with cover, metadata, play affordance). **No demo pages** (`Counter.razor`, `Weather.razor` do not exist).
 - `Layout/`: `MainLayout.razor` (root layout, wraps in `AudioPlayerProvider`, hosts theme switcher), `DeepDrftMenu.razor` (branded menu bar), `NavMenu.razor` (nav list), `Pages.cs` (centralised nav index — `MenuPages` for header, `AllPages` for exhaustive list).
 - `Controls/`: Reusable components.
   - `TrackCard.razor`: Individual track display (image, name, artist, album, genre, release date). Play/pause icon controlled via `IsPaused` parameter.
@@ -34,6 +34,7 @@ All interactive UI for the site. Blazor WebAssembly. Pages, controls, the stream
   - `TrackMediaClient`: Content API. Uses named `IHttpClientFactory` client `"DeepDrft.Content"`. Methods like `GetAudioStreamAsync(trackId, offset)` → `Stream`.
 - `ViewModels/`: Component state.
   - `TracksViewModel`: Scoped. Holds current page, page size, sort column, descending flag. `SetPage(pageNumber)` calls `TrackClient.GetPageAsync` and updates. Registered in `Startup.ConfigureDomainServices`.
+  - `TrackDetailViewModel`: Scoped. Holds loaded track, loading flag, not-found flag. `Load(entryKey)` fetches via `ITrackDataService` and resets all flags per call (prevents cross-navigation bleed). Registered in `Startup.ConfigureDomainServices`.
 - `Common/`: Shared utilities.
   - `DarkModeSettings.cs`: `[PersistentState]`-annotated class (single source of truth for dark mode in the client). Registered scoped.
   - `DDIcons.cs`: Hand-rolled SVG icons (gas-lamp lit/unlit for dark mode toggle).