Added a configurable Opus bitrate for audio transcription (#981)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/MindWork AI Studio/Settings/DataModel/TranscriptionOpusBitrate.cs

@@ -0,0 +1,14 @@
+namespace AIStudio.Settings.DataModel;
+
+public enum TranscriptionOpusBitrate
+{
+    // The recommended bitrate is deliberately the member with the underlying value 0: when the
+    // settings file holds a value TolerantEnumConverter cannot read, it falls back to that member.
+    // Landing on the lowest bitrate there would silently reintroduce the very defect this setting
+    // exists to prevent -- transcripts losing what was said quietly.
+    KBPS_128 = 0,
+
+    KBPS_32,
+    KBPS_64,
+    KBPS_256,
+}