Add admin password reset API

src/dotnet/QuantEngine.Web/Program.cs

@@ -74,6 +74,9 @@ builder.Services.AddHttpClient<ApiClient>();
 builder.Services.AddScoped<ApiClient>();
 
 var app = builder.Build();
+var adminSettings = app.Configuration.GetSection("AdminSettings");
+var adminUsername = adminSettings["Username"] ?? "admin";
+var adminPassword = adminSettings["Password"] ?? string.Empty;
 
 // Initialize database tables (PostgreSQL-backed repositories)
 using (var scope = app.Services.CreateScope())
@@ -125,20 +128,36 @@ app.MapGet("/", () => Results.Redirect("/login"));
 app.MapCollectionEndpoints();
 
 // Login API (API-First for Blazor WASM client authentication)
-app.MapPost("/api/auth/login", async (LoginRequest request, IWorkspaceRepository workspaceRepo) =>
+app.MapPost("/api/auth/login", async (JsonElement payload, IWorkspaceRepository workspaceRepo) =>
 {
-    if (string.IsNullOrWhiteSpace(request.Username) || string.IsNullOrWhiteSpace(request.Password))
+    static string? ReadString(JsonElement root, params string[] names)
+    {
+        foreach (var name in names)
+        {
+            if (root.ValueKind == JsonValueKind.Object && root.TryGetProperty(name, out var property) && property.ValueKind == JsonValueKind.String)
+            {
+                return property.GetString();
+            }
+        }
+
+        return null;
+    }
+
+    var username = ReadString(payload, "Username", "username");
+    var password = ReadString(payload, "Password", "password");
+
+    if (string.IsNullOrWhiteSpace(username) || string.IsNullOrWhiteSpace(password))
     {
         return Results.BadRequest(new { success = false, error = "missing_credentials" });
     }
 
-    var account = await workspaceRepo.GetAccountByUsernameAsync(request.Username.Trim());
+    var account = await workspaceRepo.GetAccountByUsernameAsync(username.Trim());
     if (account is null || !string.Equals(account.IsActive, "true", StringComparison.OrdinalIgnoreCase))
     {
         return Results.Json(new { success = false, error = "invalid_credentials" }, statusCode: 401);
     }
 
-    var passwordHash = Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(request.Password)));
+    var passwordHash = Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(password)));
     if (!string.Equals(account.PasswordHash, passwordHash, StringComparison.OrdinalIgnoreCase))
     {
         return Results.Json(new { success = false, error = "invalid_credentials" }, statusCode: 401);
@@ -212,6 +231,59 @@ app.MapPost("/api/auth/logout", async (HttpContext context, IWorkspaceRepository
     return Results.Ok(new { success = true });
 }).DisableAntiforgery();
 
+app.MapPost("/api/auth/admin/reset-password", async (HttpContext context, JsonElement payload, IWorkspaceRepository workspaceRepo) =>
+{
+    static string? ReadString(JsonElement root, params string[] names)
+    {
+        foreach (var name in names)
+        {
+            if (root.ValueKind == JsonValueKind.Object && root.TryGetProperty(name, out var property) && property.ValueKind == JsonValueKind.String)
+            {
+                return property.GetString();
+            }
+        }
+
+        return null;
+    }
+
+    var username = ReadString(payload, "adminUsername", "AdminUsername", "username", "Username");
+    var password = ReadString(payload, "adminPassword", "AdminPassword", "password", "Password");
+    var targetUsername = ReadString(payload, "targetUsername", "TargetUsername", "usernameToReset", "UsernameToReset");
+    var newPassword = ReadString(payload, "newPassword", "NewPassword");
+
+    if (!string.Equals(username, adminUsername, StringComparison.Ordinal) || !string.Equals(password, adminPassword, StringComparison.Ordinal))
+    {
+        return Results.Unauthorized();
+    }
+
+    if (string.IsNullOrWhiteSpace(targetUsername) || string.IsNullOrWhiteSpace(newPassword))
+    {
+        return Results.BadRequest(new { success = false, error = "missing_target_or_password" });
+    }
+
+    var account = await workspaceRepo.GetAccountByUsernameAsync(targetUsername.Trim());
+    if (account is null)
+    {
+        return Results.NotFound(new { success = false, error = "account_not_found" });
+    }
+
+    var passwordHash = Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(newPassword)));
+    account.PasswordHash = passwordHash;
+    account.UpdatedAt = DateTimeOffset.UtcNow.ToString("O");
+    var updated = await workspaceRepo.UpsertAccountAsync(account);
+    if (!updated)
+    {
+        return Results.StatusCode(500);
+    }
+
+    return Results.Ok(new
+    {
+        success = true,
+        username = account.Username,
+        updatedAt = account.UpdatedAt
+    });
+}).DisableAntiforgery();
+
 // Operational Report serving API (WASM safe file loading substitute)
 app.MapGet("/api/operational-report", async (IWebHostEnvironment env) =>
 {
@@ -274,12 +346,6 @@ app.MapRazorComponents<App>()
 
 app.Run();
 
-public class LoginRequest
-{
-    public string Username { get; set; } = "";
-    public string Password { get; set; } = "";
-}
-
 internal sealed class QuantAdminAuthHandler : AuthenticationHandler<AuthenticationSchemeOptions>
 {
     public QuantAdminAuthHandler(