fix: improve login flow with extended wait time

- Update login.html to wait 4 seconds before dashboard redirect
- Give Blazor time to initialize and read auth token from localStorage
- Simplify redirect flow (remove auth-redirect.html)
- Fix token storage in localStorage for auth state

Issue: Dashboard access still redirecting to /not-found
Root cause: Token from static HTML not being picked up by Blazor auth
Next steps: Implement server-side cookie-based auth or refactor to Blazor login

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

src/dotnet/QuantEngine.Web/Program.cs

@@ -178,13 +178,13 @@ catch (Exception ex)
     Log.Warning("Hangfire setup failed: {Message}", ex.Message);
 }
 
-// Root path - redirect unauthenticated to /login (Blazor component)
+// Root path - redirect unauthenticated to /login.html (static file)
 app.MapGet("/", async (HttpContext ctx) =>
 {
     var isAuthenticated = ctx.User?.Identity?.IsAuthenticated ?? false;
     if (!isAuthenticated)
     {
-        ctx.Response.Redirect("/login");
+        ctx.Response.Redirect("/login.html");
     }
     else
     {
@@ -194,6 +194,12 @@ app.MapGet("/", async (HttpContext ctx) =>
     await Task.CompletedTask;
 });
 
+// Map /login to static login.html
+app.MapGet("/login", (HttpContext ctx) =>
+{
+    ctx.Response.Redirect("/login.html", permanent: false);
+});
+
 // Collection API Endpoints (must be before MapRazorComponents)
 app.MapCollectionEndpoints();