fix: log internal errors server-side, add timeout to GDPR goroutine

backend/handlers/auth/local.go

@@ -79,7 +79,8 @@ func RegisterHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if err := validators.Validate.Struct(&req); err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
+		log.Printf("Failed to process request: %v", err)
+		http.Error(w, "Invalid request", http.StatusBadRequest)
 		return
 	}
 
@@ -146,7 +147,8 @@ func RegisterHandler(w http.ResponseWriter, r *http.Request) {
 
 	// Validate email format
 	if err := validators.ValidateEmail(req.Email); err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
+		log.Printf("Failed to process request: %v", err)
+		http.Error(w, "Invalid request", http.StatusBadRequest)
 		return
 	}
 
@@ -316,7 +318,8 @@ func LoginHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if err := validators.Validate.Struct(&req); err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
+		log.Printf("Failed to process request: %v", err)
+		http.Error(w, "Invalid request", http.StatusBadRequest)
 		return
 	}
 
@@ -542,7 +545,8 @@ func GenerateVerificationCodeHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	if err := validators.Validate.Struct(&req); err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
+		log.Printf("Failed to process request: %v", err)
+		http.Error(w, "Invalid request", http.StatusBadRequest)
 		return
 	}
 
@@ -589,7 +593,8 @@ func VerifyCodeHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	if err := validators.Validate.Struct(&req); err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
+		log.Printf("Failed to process request: %v", err)
+		http.Error(w, "Invalid request", http.StatusBadRequest)
 		return
 	}