Wire all 25 services into --randomize-services and add heterogeneous OS fingerprints

- Replace hardcoded ALL_SERVICE_NAMES=[5 services] in cli.py with
  _all_service_names() pulling dynamically from the plugin registry;
  randomize-services now draws from all 25 registered honeypots
- Add build_base field to DistroProfile: apt-compatible image for service
  Dockerfiles (ubuntu22/ubuntu20/kali get their own; others fall back to
  debian:bookworm-slim since Dockerfiles use apt-get)
- Add build_base to DeckyConfig; propagate from distro in _build_deckies
  and _build_deckies_from_ini
- Inject BASE_IMAGE build arg in composer.py for every build-based service
  so each decky's containers reflect its assigned distro
- Update all 21 service Dockerfiles: FROM debian:bookworm-slim →
  ARG BASE_IMAGE=debian:bookworm-slim / FROM ${BASE_IMAGE}
- Add tests/test_cli_service_pool.py and tests/test_composer.py (306 total)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

templates/http/Dockerfile

@@ -1,4 +1,5 @@
-FROM debian:bookworm-slim
+ARG BASE_IMAGE=debian:bookworm-slim
+FROM ${BASE_IMAGE}
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
     python3 python3-pip \