YDoc - GenServer #PID<0.24495.0> terminating

@rorymckinley notes that web pods restarted here. The first one looked to be a common-or-garden OOMKill, but the second one was due to a ... Rust issue!

Luckily there were some clues earlier in the log where something called Yex was expressing some unhappiness, and I see that it contains some rust code... so perhaps something to keep an eye on?

@stuartc indicated that the rust panic doesn't quite make sense when held up against the error on the right. the error on the right seems like an implementation issue i've bumped into in the first month of this yjs stuff, we're asking Yex to fetch a key from a ydoc and giving it a map instead.

Sentry Issue: LIGHTNING-17N

GenServer #PID<0.24495.0> terminating
** (stop) exited in: GenServer.call(#PID<77382.577474.0>, {:update_doc, #Function<6.44919662/1 in Lightning.Collaboration.WorkflowReconciler.reconcile_workflow_changes/2>}, 5000)
    ** (EXIT) no connection to [email]
    (elixir 1.18.3) lib/gen_server.ex:1128: GenServer.call/3
    (lightning 2.14.14) lib/lightning/collaboration/workflow_reconciler.ex:40: Lightning.Collaboration.WorkflowReconciler.reconcile_workflow_changes/2
    (lightning 2.14.14) lib/lightning/workflows.ex:182: Lightning.Workflows.save_workflow/3
    (lightning 2.14.14) lib/lightning_web/live/workflow_live/edit.ex:3511: LightningWeb.WorkflowLive.Edit.rerun/4
    (lightning 2.14.14) lib/lightning_web/live/workflow_live/edit.ex:2092: LightningWeb.WorkflowLive.Edit.handle_event/3
    (phoenix_live_view 1.0.18) lib/phoenix_live_view/channel.ex:509: anonymous fn/3 in Phoenix.LiveView.Channel.view_handle_event/3
    (telemetry 1.3.0) /app/deps/telemetry/src/telemetry.erl:324: :telemetry.span/3
    (phoenix_live_view 1.0.18) lib/phoenix_live_view/channel.ex:260: Phoenix.LiveView.Channel.handle_info/2
Last message: %Phoenix.Socket.Message{topic: "lv:phx-GH4AZrDo8bFnjODS", event: "event", payload: %{"event" => "rerun", "type" => "click", "value" => %{"run_id" => "dc93274a-9aa5-436c-bb80-caf709a8f783", "step_id" => "585943c1-5fd1-4cf0-9d74-a49164b41ba0", "value" => ""}}, ref: "257", join_ref: "247"}

Start with the stack trace in lib/lightning/collaboration/workflow_reconciler.ex:40 and the YDoc/Yex-related log evidence in the issue. Trace the update_doc call from Lightning.Workflows.save_workflow/3 and determine why the GenServer loses its connection or receives an invalid YDoc lookup. Done means the failure is reproducible and the underlying crash is fixed or clearly guarded by a regression test.