fix: restore WASM login page with correct routing configuration

- Restore admin/index.html to working state (relative script paths)
- Ensure MapRazorComponents + MapFallbackToFile combination
- Fix admin page routes to use relative paths (without /admin prefix)
- Add password reset API endpoint for admin account management
- Verify WASM bootstrap and login form rendering works correctly
- All admin pages now properly routed through WASM rendering pipeline

Server verification:
✅ HTML renders with login form correctly
✅ blazor.webassembly.js loads successfully
✅ admin-session.js binds form events
✅ No server-side errors in logs

Note: Client-side caching may require browser refresh (Ctrl+Shift+Delete)
to see latest WASM updates.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/TaxBaik.Web.Client/Components/Admin/Pages/Settings/SiteSettings.razor

@@ -1,4 +1,4 @@
-@page "/admin/settings"
+@page "/settings"
 @rendermode @(new InteractiveWebAssemblyRenderMode(prerender: false))
 @attribute [Authorize]
 @using System.ComponentModel.DataAnnotations