Media Contents records cannot be updated

[blms]

Attempting to update an existing media contents record results in a 400 error, which appears to originate in triple-eye-effable as a 500 on iiif-cloud:

2026-07-24T19:12:43.448009+00:00 app[web.1]: I, [2026-07-24T19:12:43.447981 #14]  INFO -- : [3e01b75e-90ab-c329-7bd5-425b69788045] Processing by Public::ResourcesController#update as */*
2026-07-24T19:12:43.448025+00:00 app[web.1]: I, [2026-07-24T19:12:43.448009 #14]  INFO -- : [3e01b75e-90ab-c329-7bd5-425b69788045]   Parameters: {"id" => "64bfe8e0-efee-49d1-89cd-02792cc31d15"}
2026-07-24T19:12:43.448316+00:00 app[web.1]: I, [2026-07-24T19:12:43.448293 #14]  INFO -- : [3e01b75e-90ab-c329-7bd5-425b69788045] Completed 500 Internal Server Error in 0ms (ActiveRecord: 0.0ms (0 queries, 0 cached) | GC: 0.0ms)
2026-07-24T19:12:43.448714+00:00 app[web.1]: E, [2026-07-24T19:12:43.448691 #14] ERROR -- : [3e01b75e-90ab-c329-7bd5-425b69788045]   
2026-07-24T19:12:43.448715+00:00 app[web.1]: [3e01b75e-90ab-c329-7bd5-425b69788045] NoMethodError (undefined method '[]' for nil):
2026-07-24T19:12:43.448716+00:00 app[web.1]: [3e01b75e-90ab-c329-7bd5-425b69788045]   
2026-07-24T19:12:43.448717+00:00 app[web.1]: [3e01b75e-90ab-c329-7bd5-425b69788045] app/controllers/public/resources_controller.rb:112:in 'Public::ResourcesController#set_resource_project_id'