Make Voxtral the only transcription provider

internal/model/job.go

@@ -119,22 +119,6 @@ type ErrorStat struct {
 	Last24h      int64  `json:"last_24h"`
 }
 
-type TranscriptionComparisonStat struct {
-	Provider        string     `json:"provider"`
-	Model           string     `json:"model,omitempty"`
-	Attempts        int64      `json:"attempts"`
-	Success         int64      `json:"success"`
-	Failed          int64      `json:"failed"`
-	SuccessRate     float64    `json:"success_rate"`
-	Wins            int64      `json:"wins"`
-	Last24hAttempts int64      `json:"last_24h_attempts"`
-	Last24hSuccess  int64      `json:"last_24h_success"`
-	AvgDurationMS   int64      `json:"avg_duration_ms"`
-	P50DurationMS   int64      `json:"p50_duration_ms"`
-	AvgTextChars    int64      `json:"avg_text_chars"`
-	LastAt          *time.Time `json:"last_at,omitempty"`
-}
-
 type OwnerStat struct {
 	OwnerService string `json:"owner_service"`
 	TaskType     string `json:"task_type"`