feat(p12-w2): track-cardinal high-res waveform fetch + bridge rewire

Add GET api/track/{trackEntryKey}/waveform/high-res (+ proxy), ITrackDataService.GetTrackWaveform; rewire visualizer to resolve the current track's EntryKey and re-fetch on track change. Retire the client mix-waveform read path.

DeepDrftPublic.Client/Services/IReleaseDataService.cs

@@ -24,11 +24,4 @@ public interface IReleaseDataService
 
     /// <summary>Single release resolved by its opaque public EntryKey, with both metadata satellites (nulls for non-matching media).</summary>
     Task<ApiResult<ReleaseDto>> GetByEntryKey(string entryKey);
-
-    /// <summary>
-    /// The Mix waveform datum for a release addressed by its public EntryKey. Success with a value
-    /// when present; success with a null value when no datum is stored (a valid state, not a failure);
-    /// failure on any other transport error.
-    /// </summary>
-    Task<ApiResult<WaveformProfileDto?>> GetMixWaveform(string entryKey);
 }

DeepDrftPublic.Client/Services/ITrackDataService.cs

@@ -30,6 +30,14 @@ public interface ITrackDataService
 
     Task<ApiResult<TrackDto>> GetTrack(string trackId);
 
+    /// <summary>
+    /// The per-track high-res waveform datum, addressed by the track's EntryKey (phase-12 §5b — the
+    /// datum is the track's; the release is only addressing context). Success with a value when a
+    /// high-res datum is stored; success with a null value when none is (a not-yet-backfilled track —
+    /// a valid state, not a failure, the visualizer blanks); failure on any other transport error.
+    /// </summary>
+    Task<ApiResult<WaveformProfileDto?>> GetTrackWaveform(string trackEntryKey);
+
     /// <summary>
     /// Fetches a random track from the public library for instant play. Success with a value on a
     /// hit; success with a null value when the library is empty (a valid state, not a failure);

DeepDrftPublic.Client/Services/ReleaseClientDataService.cs

@@ -31,7 +31,4 @@ public class ReleaseClientDataService : IReleaseDataService
 
     public Task<ApiResult<ReleaseDto>> GetByEntryKey(string entryKey)
         => _releaseClient.GetByEntryKey(entryKey);
-
-    public Task<ApiResult<WaveformProfileDto?>> GetMixWaveform(string entryKey)
-        => _releaseClient.GetMixWaveform(entryKey);
 }

DeepDrftPublic.Client/Services/TrackClientDataService.cs

@@ -39,6 +39,9 @@ public class TrackClientDataService : ITrackDataService
     public Task<ApiResult<TrackDto>> GetTrack(string trackId)
         => _trackClient.GetTrack(trackId);
 
+    public Task<ApiResult<WaveformProfileDto?>> GetTrackWaveform(string trackEntryKey)
+        => _trackClient.GetTrackWaveform(trackEntryKey);
+
     public Task<ApiResult<TrackDto?>> GetRandomTrack()
         => _trackClient.GetRandom();
 }