Riduce reload MediaMTX in live e allinea ingest mobile al preset qualità.

Evita patch recording ripetute che distruggevano i muxer HLS (500 ops) e fa encoderare 1080p/720p con codec e bitrate coerenti al wizard.

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

backend/spec/services/sessions/select_quality_spec.rb

@@ -0,0 +1,14 @@
+require "rails_helper"
+
+RSpec.describe Sessions::SelectQuality do
+  it "richiede più upload per 1080p rispetto a 720p" do
+    expect(described_class.call(upload_mbps: 4.4)[:id]).to eq("720p_30_4mbps")
+    expect(described_class.call(upload_mbps: 5.0)[:id]).to eq("1080p_30_4.5mbps")
+  end
+
+  it "consente 1080p solo con upload sufficiente" do
+    preset = described_class.call(upload_mbps: 4.5)
+
+    expect(preset[:id]).to eq("1080p_30_4.5mbps")
+  end
+end