fix: explicitly cache images to prevent unexpected behavior

backend/internal/utils/http_util.go

@@ -1,8 +1,11 @@
 package utils
 
 import (
+	"github.com/gin-gonic/gin"
 	"net/http"
+	"strconv"
 	"strings"
+	"time"
 )
 
 // BearerAuth returns the value of the bearer token in the Authorization header if present
@@ -16,3 +19,14 @@ func BearerAuth(r *http.Request) (string, bool) {
 
 	return "", false
 }
+
+// SetCacheControlHeader sets the Cache-Control header for the response.
+func SetCacheControlHeader(ctx *gin.Context, maxAge, staleWhileRevalidate time.Duration) {
+	_, ok := ctx.GetQuery("skipCache")
+	if !ok {
+		maxAgeSeconds := strconv.Itoa(int(maxAge.Seconds()))
+		staleWhileRevalidateSeconds := strconv.Itoa(int(staleWhileRevalidate.Seconds()))
+		ctx.Header("Cache-Control", "public, max-age="+maxAgeSeconds+", stale-while-revalidate="+staleWhileRevalidateSeconds)
+	}
+
+}