Implement WhisperX HTTP adapter

internal/adapters/whisperx/client.go

@@ -1,7 +1,10 @@
 // Package whisperx declares the adapter contract for WhisperX transcription.
 package whisperx
 
-import "context"
+import (
+	"context"
+	"time"
+)
 
 // TODO: implement a real WhisperX HTTP client adapter.
 
@@ -20,5 +23,8 @@ type TranscribeRequest struct {
 // TranscribeResult describes the transcript output and adapter metadata.
 type TranscribeResult struct {
 	OutputRawTranscriptPath string
+	Attempts                int
+	HTTPStatus              int
+	Duration                time.Duration
 	Metadata                map[string]any
 }