Fix race create sessione su CPX: ready solo dopo MediaMTX.

I nodi cloud restano in provisioning finché :9997 risponde; retry su create_path e 503 retryable se l’ingest è ancora irraggiungibile.

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

backend/spec/services/mediamtx/client_create_path_retry_spec.rb

@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+RSpec.describe Mediamtx::Client do
+  describe "#create_path" do
+    let(:session) do
+      user = User.create!(email: "mtx-#{SecureRandom.hex(4)}@example.com", name: "M", password: "Password123", role: "coach")
+      club = Club.create!(name: "MtxClub-#{SecureRandom.hex(3)}", sport: "volleyball")
+      team = club.teams.create!(name: "T", sport: "volleyball", slug: "mtx-#{SecureRandom.hex(4)}")
+      match = team.matches.create!(opponent_name: "X", scheduled_at: 1.hour.from_now)
+      StreamSession.create!(match: match, user: user, platform: "matchlivetv", status: "idle")
+    end
+
+    it "retries Faraday connection failures then succeeds" do
+      ENV["MEDIAMTX_CREATE_RETRIES"] = "3"
+      ENV["MEDIAMTX_CREATE_RETRY_BASE_SECS"] = "0"
+
+      client = described_class.new(base_url: "http://mtx.test:9997")
+      conn = instance_double(Faraday::Connection)
+      client.instance_variable_set(:@conn, conn)
+
+      fail_once = Faraday::ConnectionFailed.new("Connection refused")
+      ok = instance_double(Faraday::Response, success?: true, status: 200, body: {})
+
+      expect(conn).to receive(:post).once.and_raise(fail_once)
+      expect(conn).to receive(:post).once.and_return(ok)
+
+      expect(client.create_path(session)).to eq(true)
+    ensure
+      ENV.delete("MEDIAMTX_CREATE_RETRIES")
+      ENV.delete("MEDIAMTX_CREATE_RETRY_BASE_SECS")
+    end
+
+    it "raises after exhausting connection retries" do
+      ENV["MEDIAMTX_CREATE_RETRIES"] = "2"
+      ENV["MEDIAMTX_CREATE_RETRY_BASE_SECS"] = "0"
+
+      client = described_class.new(base_url: "http://mtx.test:9997")
+      conn = instance_double(Faraday::Connection)
+      client.instance_variable_set(:@conn, conn)
+      allow(conn).to receive(:post).and_raise(Faraday::ConnectionFailed.new("Connection refused"))
+
+      expect { client.create_path(session) }.to raise_error(Faraday::ConnectionFailed)
+    ensure
+      ENV.delete("MEDIAMTX_CREATE_RETRIES")
+      ENV.delete("MEDIAMTX_CREATE_RETRY_BASE_SECS")
+    end
+  end
+end