feat(core): add password hashing and token generation interfaces

src/FiscalOS.API/Login/Response.cs

@@ -1,3 +1,16 @@
 namespace FiscalOS.API.Login;
 
-internal sealed record Response(string AccessToken);
+internal sealed record Response
+{
+  public string AccessToken { get; init; }
+
+  private Response(string accessToken)
+  {
+    AccessToken = accessToken;
+  }
+
+  public static Response From(string accessToken)
+  {
+    return new(accessToken);
+  }
+}