Add WhisperX configuration contract

internal/config/validate.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"fmt"
+	"net/url"
 	"strings"
 	"time"
 )
@@ -32,10 +33,10 @@ func validatePipeline(cfg *PipelineConfig) error {
 	if strings.TrimSpace(cfg.Workspace.Root) == "" {
 		return fmt.Errorf("pipeline.workspace.root is required")
 	}
-
-	if err := validateDuration("pipeline.whisperx.timeout", cfg.WhisperX.Timeout); err != nil {
+	if err := validateWhisperX(cfg.WhisperX); err != nil {
 		return err
 	}
+
 	if err := validateDuration("pipeline.seriatim.timeout", cfg.Seriatim.Timeout); err != nil {
 		return err
 	}
@@ -52,6 +53,38 @@ func validatePipeline(cfg *PipelineConfig) error {
 	return nil
 }
 
+func validateWhisperX(cfg WhisperXConfig) error {
+	if strings.TrimSpace(cfg.TranscribeURL) == "" {
+		return fmt.Errorf("pipeline.whisperx.transcribe_url is required")
+	}
+	u, err := url.Parse(cfg.TranscribeURL)
+	if err != nil || u.Scheme == "" || u.Host == "" {
+		if err != nil {
+			return fmt.Errorf("pipeline.whisperx.transcribe_url must be a valid URL: %w", err)
+		}
+		return fmt.Errorf("pipeline.whisperx.transcribe_url must be a valid URL")
+	}
+	if err := validateDuration("pipeline.whisperx.timeout", cfg.Timeout); err != nil {
+		return err
+	}
+	if err := validateDuration("pipeline.whisperx.retry_delay", cfg.RetryDelay); err != nil {
+		return err
+	}
+	if cfg.Retries == nil {
+		return fmt.Errorf("pipeline.whisperx.retries must be set (defaults should populate this)")
+	}
+	if *cfg.Retries < 0 {
+		return fmt.Errorf("pipeline.whisperx.retries must be >= 0")
+	}
+	if cfg.Concurrency == nil {
+		return fmt.Errorf("pipeline.whisperx.concurrency must be set (defaults should populate this)")
+	}
+	if *cfg.Concurrency <= 0 {
+		return fmt.Errorf("pipeline.whisperx.concurrency must be > 0")
+	}
+	return nil
+}
+
 func validateSession(cfg *SessionConfig) error {
 	if strings.TrimSpace(cfg.SessionID) == "" {
 		return fmt.Errorf("session.session_id is required")