Refactor setup to Python

[madebygps]

Move CTF setup and verify logic into Python packages while keeping ctf_setup.sh as a thin bootstrap.

Update Terraform contributor and release setup paths, add release packaging, and refresh CTF testing guidance.

[Copilot]

Pull request overview

This PR refactors the CTF setup and verification logic from a single Bash script (ctf_setup.sh) into a Python package layout (setup/ and verify/), keeping ctf_setup.sh as a thin cloud-init bootstrap. It also introduces a two-mode Terraform deployment (release vs. contributor) for all three cloud providers, adds a release-packaging GitHub workflow, and refreshes contributor and testing documentation. Challenge 9 is reworked from mutating /etc/resolv.conf to writing a systemd-resolved drop-in.

Changes:

• Replace monolithic Bash setup and verify shell function with Python packages (setup/, verify/) bootstrapped via uv/Python 3.13, while preserving flag format, instance ID, HMAC-SHA256 token, and state file layout.
• Split Terraform startup into release mode (download SHA256-verified release tarball) and contributor mode (local bootstrap + SSH upload of local ctf_setup.sh, setup, verify); add setup_release_tag and rework null_resource to depend on use_local_setup.
• Add .github/workflows/release-setup.yml to build a deterministic linux-ctfs-setup.tar.gz plus checksum on release; update tests, docs, and challenge 9 to use the systemd-resolved drop-in.

Show a summary per file

File	Description
ctf_setup.sh	Slimmed to a cloud-init bootstrap that logs to /var/log/ctf_setup.log, installs uv/Python 3.13, runs setup, installs verify, and writes done/failed markers.
setup/pyproject.toml, setup/main.py, setup/helpers.py, setup/system.py, setup/state.py, setup/flags.py	New Python setup package: system configuration, flag generation, state file writing, helper utilities.
setup/challenges/*.py	One module per challenge (ch01–ch18) replacing the inline Bash setup; ch09 now writes /etc/systemd/resolved.conf.d/ctf-dns.conf.
verify/pyproject.toml, verify/src/verify/{__init__,__main__,commands,state}.py	New verify CLI built on rich/pyfiglet, preserving commands (progress, list, hint, time, export, numeric flag check) and token format.
aws/main.tf, azure/main.tf, gcp/main.tf	Add release/contributor mode locals, setup_release_tag variable, conditional null_resource.local_setup, and update outputs.
aws/README.md, azure/README.md, gcp/README.md, README.md, CONTRIBUTING.md	Document release vs. contributor mode, new setup-readiness markers, and updated local checks.
.github/workflows/release-setup.yml	New workflow to build deterministic linux-ctfs-setup.tar.gz + SHA256 and upload to releases.
.github/skills/ctf-testing/deploy_and_test.sh, .github/skills/ctf-testing/test_ctf_challenges.sh, .github/skills/ctf-testing/SKILL.md	Add _wait_for_setup marker polling, switch ch09 test to drop-in, fix pass → _pass, restructure SKILL guidance.
.gitignore	Ignore __pycache__/, *.py[cod], .venv/.

Copilot's findings

• Files reviewed: 43/44 changed files
• Comments generated: 0