fix: resolve context key cycle for admin check

internal/middleware/admin.go

@@ -4,6 +4,7 @@ import (
 	"net/http"
 
 	"mal/internal/db"
+	webcontext "mal/web/context"
 	"mal/web/shared/admin"
 )
 
@@ -13,7 +14,7 @@ func IsAdmin(user *database.User) bool {
 
 func RequireAdmin(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		user, ok := r.Context().Value(UserContextKey).(*database.User)
+		user, ok := r.Context().Value(webcontext.UserKey).(*database.User)
 		if !ok || user == nil {
 			http.Redirect(w, r, "/login", http.StatusFound)
 			return