Phase 3: move service layer, serializers and DTOs into WarpEngine + dummy-app test suite

- all catalog services (update/software/highlighted/builds/file/file-manager/
  download/image + SoftwareResponseBuilder), the SoftwareUpdater platform
  services and their concerns, Blueprinter serializers (incl. TimestampFields)
  and the 4 DTOs now live in the engine under WarpEngine::
- constantize dispatch strings use absolute names
  (WarpEngine::SoftwareUpdater::<Platform>Service)
- container paths read from WarpEngine.config everywhere (FileService,
  DownloadService, FileManagerService, ArchiveExtraction, ReleaseSerializer
  path rewriting); FileManagerService base path is now lazy
- engine requires blueprinter itself; gemspec declares blueprinter + rubyzip
- engine test suite: spec/dummy app (mysql warp_engine_test, catalog-only
  schema), rails_helper with engine-local factories; catalog model/service
  specs and factories moved from the host
- host suite keeps TTG specs and loads catalog factories from the engine

Verified: engine suite 40 green, host suite 14 green, /api/software and
/api/builds byte-identical to baselines, admin OK.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

spec/models/software_spec.rb

@@ -0,0 +1,25 @@
+require "rails_helper"
+
+RSpec.describe WarpEngine::Software, type: :model do
+  subject { build(:software) }
+
+  it { should validate_presence_of(:name) }
+  it { should validate_presence_of(:title) }
+  it { should validate_presence_of(:platform) }
+  # MySQL utf8mb4_0900_ai_ci collation: az egyediség DB-szinten case-insensitive
+  it { should validate_uniqueness_of(:name).case_insensitive }
+
+  # a törlést a DB-szintű ON DELETE CASCADE végzi, a modellen nincs dependent opció
+  it { should have_many(:releases) }
+  it { should have_many(:external_links) }
+  it { should have_many(:software_images).dependent(:destroy) }
+
+  describe "default scope" do
+    it "excludes soft-deleted records" do
+      active = create(:software)
+      create(:software, deleted_at: Time.current)
+
+      expect(WarpEngine::Software.all).to eq([active])
+    end
+  end
+end