POST /tutorial/update echoes tutorial_step back and saves it to
Viewer.MissionData.TutorialState. is_skip=1 is handled server-side
by honoring whatever tutorial_step value the client sends (client
already sends 100 when skipping). Adds TutorialUpdateRequest DTO,
TutorialUpdateResponse DTO, injects SVSimDbContext into
TutorialController, and adds GetViewerTutorialStateAsync helper to
SVSimTestFactory.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Returns an empty data object (result_code=1 from middleware envelope).
Client uses SkipAllNetworkChecks so the response body is never read.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
