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/Clients/ReleaseClient.cs

@@ -83,27 +83,4 @@ public class ReleaseClient
             ? ApiResult<ReleaseDto>.CreatePassResult(release)
             : ApiResult<ReleaseDto>.CreateFailResult("Failed to deserialize response");
     }
-
-    /// <summary>
-    /// Fetches the high-res waveform datum for a Mix release, addressed by its public EntryKey. A 404
-    /// means no datum is stored (not yet generated, or not a Mix) — a valid state, so it returns a pass
-    /// result with a null value. Any other non-success status is a genuine failure.
-    /// </summary>
-    public async Task<ApiResult<WaveformProfileDto?>> GetMixWaveform(string entryKey)
-    {
-        var response = await _http.GetAsync($"api/release/{Uri.EscapeDataString(entryKey)}/mix/waveform");
-
-        if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
-            return ApiResult<WaveformProfileDto?>.CreatePassResult(null);
-
-        if (!response.IsSuccessStatusCode)
-            return ApiResult<WaveformProfileDto?>.CreateFailResult($"HTTP {(int)response.StatusCode}");
-
-        var json = await response.Content.ReadAsStringAsync();
-        var profile = JsonSerializer.Deserialize<WaveformProfileDto>(json, JsonOptions);
-
-        return profile is not null
-            ? ApiResult<WaveformProfileDto?>.CreatePassResult(profile)
-            : ApiResult<WaveformProfileDto?>.CreateFailResult("Failed to deserialize response");
-    }
 }

DeepDrftPublic.Client/Clients/TrackClient.cs

@@ -129,6 +129,33 @@ public class TrackClient
             : ApiResult<List<GenreSummaryDto>>.CreateFailResult("Failed to deserialize response");
     }
 
+    /// <summary>
+    /// Fetches the per-track high-res waveform datum, addressed by the track's EntryKey (phase-12 §5b).
+    /// A 404 means no high-res datum is stored (a track not yet backfilled) — a valid state, so it
+    /// returns a pass result with a null value and the visualizer blanks gracefully. Any other
+    /// non-success status is a genuine failure.
+    /// </summary>
+    public async Task<ApiResult<WaveformProfileDto?>> GetTrackWaveform(string trackEntryKey)
+    {
+        var response = await _http.GetAsync($"api/track/{Uri.EscapeDataString(trackEntryKey)}/waveform/high-res");
+
+        if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
+            return ApiResult<WaveformProfileDto?>.CreatePassResult(null);
+
+        if (!response.IsSuccessStatusCode)
+            return ApiResult<WaveformProfileDto?>.CreateFailResult($"HTTP {(int)response.StatusCode}");
+
+        var json = await response.Content.ReadAsStringAsync();
+        var profile = JsonSerializer.Deserialize<WaveformProfileDto>(json, new JsonSerializerOptions
+        {
+            PropertyNameCaseInsensitive = true
+        });
+
+        return profile is not null
+            ? ApiResult<WaveformProfileDto?>.CreatePassResult(profile)
+            : ApiResult<WaveformProfileDto?>.CreateFailResult("Failed to deserialize response");
+    }
+
     public async Task<ApiResult<TrackDto>> GetTrack(string entryKey)
     {
         var response = await _http.GetAsync($"api/track/meta/by-key/{Uri.EscapeDataString(entryKey)}");