Corregge il provisioning Hetzner: Faraday, cloud-init e default cpx12.

Sistemati path API /v1, AppArmor/auth MediaMTX sul nodo e defaults nbg1 così lo smoke Cloud è ripetibile.

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

backend/spec/services/streams/dns_providers/hetzner_spec.rb

@@ -5,7 +5,7 @@ require "rails_helper"
 RSpec.describe Streams::DnsProviders::Hetzner do
   let(:stubs) { Faraday::Adapter::Test::Stubs.new }
   let(:conn) do
-    Faraday.new(url: "https://api.hetzner.cloud/v1") do |f|
+    Faraday.new(url: Streams::DnsProviders::Hetzner::API) do |f|
       f.request :json
       f.response :json
       f.adapter :test, stubs
@@ -16,8 +16,8 @@ RSpec.describe Streams::DnsProviders::Hetzner do
   after { stubs.verify_stubbed_calls }
 
   it "upserts an A record (delete then create)" do
-    stubs.delete("/zones/mltv-stream.net/rrsets/ingest-01/A") { [404, {}, ""] }
-    stubs.post("/zones/mltv-stream.net/rrsets") do |env|
+    stubs.delete("https://api.hetzner.cloud/v1/zones/mltv-stream.net/rrsets/ingest-01/A") { [404, {}, ""] }
+    stubs.post("https://api.hetzner.cloud/v1/zones/mltv-stream.net/rrsets") do |env|
       body = JSON.parse(env.body)
       expect(body["name"]).to eq("ingest-01")
       expect(body["type"]).to eq("A")
@@ -29,7 +29,7 @@ RSpec.describe Streams::DnsProviders::Hetzner do
   end
 
   it "deletes an A record" do
-    stubs.delete("/zones/mltv-stream.net/rrsets/ingest-01/A") { [204, {}, ""] }
+    stubs.delete("https://api.hetzner.cloud/v1/zones/mltv-stream.net/rrsets/ingest-01/A") { [204, {}, ""] }
     expect(provider.delete_a("ingest-01.mltv-stream.net")).to eq(true)
   end
 end