feat: add Vite configuration for Tiku.PlatformAdmin.Web and update documentation

- Introduced Vite configuration files (vite.config.js, vite.config.ts, vite.config.d.ts) for the React frontend.
- Configured server proxy settings for API endpoints.
- Added Vitest configuration files (vitest.config.js, vitest.config.ts, vitest.config.d.ts) for testing.
- Updated architecture overview to reflect the separation of the platform admin frontend into its own React project.
- Modified quickstart documentation to guide users on starting the platform admin frontend.

Tiku.Api/Configuration/ApplicationBuilderExtensions.cs

@@ -27,8 +27,6 @@ public static class ApplicationBuilderExtensions
         app.UseForwardedHeaders();
         app.UseHttpsRedirection();
         app.UseResponseCompression();
-        app.UseDefaultFiles();
-        app.UseStaticFiles();
         app.UseRouting();
         app.UseCors(CorsOptions.PolicyName);
         app.UseMiddleware<TenantResolutionMiddleware>();