Alza soft capacity fase A e aggiunge quiet hours CPX notturne.

Home a 4 e cloud a 6 con MAX_NODES=12 (~76 soft); di notte (02–07 Europe/Rome) niente scale-out/warm-spare e sweeper che chiude i CPX idle.

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

backend/spec/services/streams/quiet_hours_spec.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+RSpec.describe Streams::QuietHours do
+  def with_env(vars)
+    previous = vars.keys.index_with { |k| ENV[k] }
+    vars.each { |k, v| ENV[k] = v }
+    yield
+  ensure
+    previous.each { |k, v| v.nil? ? ENV.delete(k) : ENV[k] = v }
+  end
+
+  it "is active inside the Rome window" do
+    with_env(
+      "STREAM_AUTOSCALE_QUIET_HOURS" => "02:00-07:00",
+      "STREAM_AUTOSCALE_QUIET_TZ" => "Europe/Rome"
+    ) do
+      now = Time.find_zone!("Europe/Rome").local(2026, 9, 5, 3, 30)
+      expect(described_class.active?(now: now)).to eq(true)
+    end
+  end
+
+  it "is inactive outside the window" do
+    with_env(
+      "STREAM_AUTOSCALE_QUIET_HOURS" => "02:00-07:00",
+      "STREAM_AUTOSCALE_QUIET_TZ" => "Europe/Rome"
+    ) do
+      now = Time.find_zone!("Europe/Rome").local(2026, 9, 5, 10, 0)
+      expect(described_class.active?(now: now)).to eq(false)
+    end
+  end
+
+  it "can be disabled with off" do
+    with_env("STREAM_AUTOSCALE_QUIET_HOURS" => "off") do
+      now = Time.find_zone!("Europe/Rome").local(2026, 9, 5, 3, 0)
+      expect(described_class.active?(now: now)).to eq(false)
+    end
+  end
+end