Add refetchThemes function to event theme context and usage

Introduce a new `refetchThemes` function in the event theme context to allow for refreshing event theme data. Update `EventThemeForm` to call `refetchThemes` after updating a theme, ensuring the data stays synchronized. This enhances the consistency of the UI after changes to event themes.

frontend/src/components/event-themes/event-theme-form.tsx

@@ -36,7 +36,7 @@ type ThemeFormProps = {
 
 export function EventThemeForm({ theme, mode }: ThemeFormProps) {
   const router = useRouter();
-  const { createTheme, updateTheme } = useEventThemes();
+  const { createTheme, updateTheme, refetchThemes } = useEventThemes();
 
   // Form state
   const [formState, setFormState] = useState<
@@ -202,6 +202,7 @@ export function EventThemeForm({ theme, mode }: ThemeFormProps) {
         router.push("/dashboard/event-themes");
       } else if (mode === "edit" && theme) {
         await updateTheme(theme.id, formState as EventThemeUpdate);
+        await refetchThemes();
         router.push("/dashboard/event-themes");
       }
     } catch (err) {

frontend/src/context/event-theme-context.tsx

@@ -7,7 +7,12 @@ import React, {
   useContext,
   useState,
 } from "react";
-import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
+import {
+  RefetchOptions,
+  useMutation,
+  useQuery,
+  useQueryClient,
+} from "@tanstack/react-query";
 import {
   getEventThemeOptions,
   listEventThemesOptions,
@@ -26,6 +31,9 @@ interface EventThemesContextState {
   isLoadingThemes: boolean;
   isLoadingTheme: boolean;
 
+  refetchThemes: (
+    options?: RefetchOptions | undefined,
+  ) => Promise<any | undefined>;
   createTheme: (
     data: EventThemeCreate,
   ) => Promise<EventThemeResponse | undefined>;
@@ -48,6 +56,10 @@ const defaultEventThemesState: EventThemesContextState = {
   isLoadingThemes: false,
   isLoadingTheme: false,
 
+  refetchThemes: async () => {
+    throw new Error("EventThemesProvider not initialized");
+  },
+
   createTheme: async () => {
     throw new Error("EventThemesProvider not initialized");
   },
@@ -95,6 +107,7 @@ export const EventThemesProvider: React.FC<EventThemesProviderProps> = ({
     data: themes,
     isLoading: isLoadingThemes,
     error,
+    refetch: refetchThemes,
   } = useQuery({
     ...listEventThemesOptions(),
     refetchOnWindowFocus: "always",
@@ -124,10 +137,11 @@ export const EventThemesProvider: React.FC<EventThemesProviderProps> = ({
   });
 
   const updateMutation = useMutation({
-    mutationFn: ({ id, data }: { id: string; data: EventThemeUpdate }) =>
+    mutationFn: ({ id, data }: { id: string; data: EventThemeUpdate }) => {
-      updateEventTheme({ path: { theme_id: id }, body: data }).then(
+      return updateEventTheme({ path: { theme_id: id }, body: data }).then(
         (result) => result.data,
-      ),
+      );
+    },
 
     onSuccess: () =>
       queryClient.invalidateQueries({
@@ -165,7 +179,7 @@ export const EventThemesProvider: React.FC<EventThemesProviderProps> = ({
     themes,
     isLoadingThemes,
     isLoadingTheme,
-
+    refetchThemes,
     createTheme,
     updateTheme,
     deleteTheme,