fix(training): resolve Gin route conflicts and fix TTS Dockerfile

- Fix route param conflict: /content/publish/:id instead of /content/:id/publish
- Fix route conflict: /media/module/:moduleId for module media list
- Use Piper binary instead of pip package (ARM64 compatibility)
- Update frontend API URLs to match new routes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ai-compliance-sdk/cmd/server/main.go

@@ -721,11 +721,11 @@ func main() {
 			trainingRoutes.POST("/content/generate-all", trainingHandlers.GenerateAllContent)
 			trainingRoutes.POST("/content/generate-all-quiz", trainingHandlers.GenerateAllQuizzes)
 			trainingRoutes.GET("/content/:moduleId", trainingHandlers.GetContent)
-			trainingRoutes.POST("/content/:id/publish", trainingHandlers.PublishContent)
+			trainingRoutes.POST("/content/publish/:id", trainingHandlers.PublishContent)
 
 			// Audio/Media
 			trainingRoutes.POST("/content/:moduleId/generate-audio", trainingHandlers.GenerateAudio)
-			trainingRoutes.GET("/media/:moduleId", trainingHandlers.GetModuleMedia)
+			trainingRoutes.GET("/media/module/:moduleId", trainingHandlers.GetModuleMedia)
 			trainingRoutes.GET("/media/:id/url", trainingHandlers.GetMediaURL)
 			trainingRoutes.POST("/media/:id/publish", trainingHandlers.PublishMedia)