Implement Site Builder Metadata and Enhance Wizard Functionality

- Introduced new models for Site Builder options, including BusinessType, AudienceProfile, BrandPersonality, and HeroImageryDirection.
- Added serializers and views to handle metadata for dropdowns in the Site Builder wizard.
- Updated the SiteBuilderWizard component to load and display metadata, improving user experience with dynamic options.
- Enhanced BusinessDetailsStep and StyleStep components to utilize new metadata for business types and brand personalities.
- Refactored state management in builderStore to include metadata loading and error handling.
- Updated API service to fetch Site Builder metadata, ensuring seamless integration with the frontend.

frontend/src/services/siteBuilder.api.ts

@@ -8,6 +8,7 @@ import type {
   PageBlueprint,
   SiteStructure,
   BuilderFormData,
+  SiteBuilderMetadata,
 } from '../types/siteBuilder';
 
 export interface CreateBlueprintPayload {
@@ -121,5 +122,12 @@ export const siteBuilderApi = {
     // Handle unified response format
     return response?.data || response;
   },
+
+  /**
+   * Load dropdown metadata for wizard fields
+   */
+  async getMetadata(): Promise<SiteBuilderMetadata> {
+    return fetchAPI('/v1/site-builder/metadata/');
+  },
 };