feat(events): Sync from Branding button in gallery theme customizer + clarified default inheritance

frontend/src/components/admin/ThemeCustomizerEnhanced.tsx

@@ -60,6 +60,12 @@ interface ThemeCustomizerEnhancedProps {
   // props are omitted (e.g. event-level theme editor), the section is hidden.
   forceColorMode?: 'dark' | 'light' | null;
   onForceColorModeChange?: (mode: 'dark' | 'light' | null) => void;
+  // Sync palette from Branding. When provided, a small button appears in
+  // the colour-pickers section header. The caller resolves the active
+  // Branding theme and fires onChange with the merged 8-token values —
+  // only the colour tokens swap, layout/header/typography stay put so an
+  // admin who's already arranged the structure can pull just the palette.
+  onSyncFromBranding?: () => void;
 }
 
 /**
@@ -167,7 +173,8 @@ export const ThemeCustomizerEnhanced: React.FC<ThemeCustomizerEnhancedProps> = (
   cssTemplateId,
   onCssTemplateChange,
   forceColorMode,
-  onForceColorModeChange
+  onForceColorModeChange,
+  onSyncFromBranding
 }) => {
   const { t } = useTranslation();
   const [localTheme, setLocalTheme] = useState<ThemeConfig>(value);
@@ -878,10 +885,26 @@ export const ThemeCustomizerEnhanced: React.FC<ThemeCustomizerEnhancedProps> = (
 
       {/* Color Customization */}
       <Card className="p-6">
-        <h3 className="text-lg font-semibold text-neutral-900 dark:text-neutral-100 mb-4 flex items-center gap-2">
+        <div className="flex items-center justify-between gap-2 mb-4">
+          <h3 className="text-lg font-semibold text-neutral-900 dark:text-neutral-100 flex items-center gap-2">
             <Palette className="w-5 h-5" />
             {t('branding.colors')}
           </h3>
+          {/* "Sync from Branding" — caller-supplied so the customizer
+              doesn't have to know how to resolve the Branding theme.
+              Used in event create/edit to reset palette to site colours. */}
+          {onSyncFromBranding && (
+            <Button
+              type="button"
+              variant="outline"
+              size="sm"
+              leftIcon={<RotateCcw className="w-4 h-4" />}
+              onClick={onSyncFromBranding}
+            >
+              {t('branding.syncFromBranding', 'Sync from Branding')}
+            </Button>
+          )}
+        </div>
 
         {/* Color Mode Selector */}
         <div className="mb-6">

frontend/src/pages/admin/CreateEventPage.tsx

@@ -242,6 +242,9 @@ export const CreateEventPage: React.FC = () => {
 
   // Apply the global Branding default theme on first load so admins who set a
   // site-wide default in Branding actually see it on new events (#323).
+  // This is the "always inherit colours from Branding" guarantee — every new
+  // gallery starts with the site palette unless the admin then picks a preset
+  // or hits Sync from Branding inside the customizer to re-pull it later.
   const brandingThemeApplied = useRef(false);
   useEffect(() => {
     if (brandingThemeApplied.current) return;
@@ -597,6 +600,36 @@ export const CreateEventPage: React.FC = () => {
                     onPresetChange={handlePresetChange}
                     showGalleryLayouts={true}
                     hideActions={true}
+                    onSyncFromBranding={() => {
+                      // Pull the 8 colour tokens (+ legacy primary alias) from
+                      // the global Branding theme into the current event theme.
+                      // Layout / header / typography are kept untouched so an
+                      // admin who has already arranged structure can refresh
+                      // just the palette.
+                      const branding = settings?.theme_config as ThemeConfig | undefined;
+                      if (!branding) {
+                        toast.error(t('toast.brandingThemeMissing', 'No branding theme has been saved yet.'));
+                        return;
+                      }
+                      setFormData(prev => ({
+                        ...prev,
+                        theme_preset: 'custom',
+                        theme_config: {
+                          ...prev.theme_config,
+                          primaryColor: branding.primaryColor,
+                          accentColor: branding.accentColor,
+                          accentDarkColor: branding.accentDarkColor,
+                          backgroundColor: branding.backgroundColor,
+                          surfaceColor: branding.surfaceColor,
+                          elevatedColor: branding.elevatedColor,
+                          surfaceBorderColor: branding.surfaceBorderColor,
+                          textColor: branding.textColor,
+                          mutedTextColor: branding.mutedTextColor,
+                          colorMode: branding.colorMode ?? prev.theme_config.colorMode,
+                        },
+                      }));
+                      toast.success(t('toast.brandingPaletteSynced', 'Palette synced from Branding.'));
+                    }}
                   />
                   
                   {/* Gallery Preview */}

frontend/src/pages/admin/EventDetailsPage.tsx

@@ -2095,6 +2095,34 @@ export const EventDetailsPage: React.FC = () => {
                     }
                   }
                 }}
+                onSyncFromBranding={() => {
+                  // Reset only the 8 colour tokens to the site Branding —
+                  // layout, header, typography all stay so the admin doesn't
+                  // lose tweaks made for this specific event.
+                  const branding = publicSettings?.theme_config as ThemeConfig | undefined;
+                  if (!branding) {
+                    toast.error(t('toast.brandingThemeMissing', 'No branding theme has been saved yet.'));
+                    return;
+                  }
+                  const base = currentTheme || GALLERY_THEME_PRESETS.default.config;
+                  const merged: ThemeConfig = {
+                    ...base,
+                    primaryColor: branding.primaryColor,
+                    accentColor: branding.accentColor,
+                    accentDarkColor: branding.accentDarkColor,
+                    backgroundColor: branding.backgroundColor,
+                    surfaceColor: branding.surfaceColor,
+                    elevatedColor: branding.elevatedColor,
+                    surfaceBorderColor: branding.surfaceBorderColor,
+                    textColor: branding.textColor,
+                    mutedTextColor: branding.mutedTextColor,
+                    colorMode: branding.colorMode ?? base.colorMode,
+                  };
+                  setCurrentTheme(merged);
+                  setCurrentPresetName('custom');
+                  setEditForm(prev => ({ ...prev, color_theme: JSON.stringify(merged) }));
+                  toast.success(t('toast.brandingPaletteSynced', 'Palette synced from Branding.'));
+                }}
                 isPreviewMode={true}
                 showGalleryLayouts={true}
                 hideActions={true}