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

backend/handlers/scheduling/exceptional-hours.go

@@ -2,6 +2,7 @@ package scheduling
 
 import (
 	"encoding/json"
+	"log"
 	"log/slog"
 	"net/http"
 	"strconv"
@@ -131,7 +132,8 @@ func CreateExceptionalGroup(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if err := validators.Validate.Struct(&g); 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
 	}
 
@@ -302,7 +304,8 @@ func UpdateExceptionalApplications(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
 	}