refactor: migrate to src/ package + add DinD-based E2E runner with debug artifacts

- Replace legacy standalone scripts with a proper src-layout Python package
  (baudolo backup/restore/configure entrypoints via pyproject.toml)
- Remove old scripts/files (backup-docker-to-local.py, recover-docker-from-local.sh,
  databases.csv.tpl, Todo.md)
- Add Dockerfile to build the project image for local/E2E usage
- Update Makefile: build image and run E2E via external runner script
- Add scripts/test-e2e.sh:
  - start DinD + dedicated network
  - recreate DinD data volume (and shared /tmp volume)
  - pre-pull helper images (alpine-rsync, alpine)
  - load local baudolo:local image into DinD
  - run unittest E2E suite inside DinD and abort on first failure
  - on failure: dump host+DinD diagnostics and archive shared /tmp into artifacts/
- Add artifacts/ debug outputs produced by failing E2E runs (logs, events, tmp archive)

https://chatgpt.com/share/694ec23f-0794-800f-9a59-8365bc80f435

Dockerfile

@@ -0,0 +1,34 @@
+# syntax=docker/dockerfile:1
+FROM python:3.11-slim
+
+WORKDIR /app
+
+# Runtime + build essentials:
+# - rsync: required for file backup/restore
+# - ca-certificates: TLS
+# - docker-cli: needed if you want to control the host Docker engine (via /var/run/docker.sock mount)
+# - make: to delegate install logic to Makefile
+#
+# Notes:
+# - On Debian slim, the docker client package is typically "docker.io".
+# - If you only want restore-without-docker, you can drop docker.io later.
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    make \
+    rsync \
+    ca-certificates \
+    docker-cli \
+  && rm -rf /var/lib/apt/lists/*
+
+# Fail fast if docker client is missing
+RUN command -v docker
+
+COPY . .
+
+# All install decisions are handled by the Makefile.
+RUN make install
+
+# Sensible defaults (can be overridden at runtime)
+ENV PYTHONUNBUFFERED=1
+
+# Default: show CLI help
+CMD ["baudolo", "--help"]