Preserva drain/offline su home e genera slate offline nel cloud-init.

Evita che ensure_home_from_env! annulli il drain a ogni allocate, e prepara /slates/offline.mp4 sul nodo Cloud per create_path MediaMTX.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/spec/services/streams/node_registry_spec.rb

@@ -39,6 +39,16 @@ RSpec.describe Streams::NodeRegistry do
     end
   end
 
+  it "does not reset home drain/offline/error status on ensure" do
+    with_env(home_env) do
+      home = described_class.ensure_home_from_env!
+      home.update!(status: "draining")
+
+      expect(described_class.ensure_home_from_env!.status).to eq("draining")
+      expect { described_class.allocate! }.to raise_error(Streams::NodeRegistry::NoCapacityError)
+    end
+  end
+
   it "allocates the least loaded ready node" do
     with_env(home_env) do
       home = described_class.ensure_home_from_env!