Seven-task plan derived from the 2026-06-08-github-provider design
spec. Order: extract _link_pagination (pure refactor), extract
_translate_transport (pure refactor), Settings.provider + validator
(TDD), translate_github + 422-already-exists (TDD), GitHubProvider +
integration tests (port-style), wire ioc.py + CLI + docs + README +
pyproject, final validation. Resolves all five spec open items inline.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

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

…vider_label)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

…dator

- Add `provider` field (gitlab|github) with AliasChoices for SEMVERTAG_PROVIDER/PROVIDER
- Add `repo` field with AliasChoices for SEMVERTAG_REPO/GITHUB_REPOSITORY
- Add `GitHubConfig.endpoint` defaulting to "https://api.github.com"
- Add `_detect_provider_from_env()` that auto-detects from GITHUB_ACTIONS/GITLAB_CI env vars, raising ValueError on ambiguous dual-CI context
- Add `_resolve_provider` model_validator (mode="after") that auto-detects provider, then enforces github→repo and gitlab→project_id constraints
- Add `populate_by_name=True` to Settings.model_config so field names can be used in init kwargs and apply_cli_overlay
- Remove dead `project_id is None` guard in ioc._build_gitlab_provider (now enforced by validator); drop unused ConfigError import
- Cascade-fix existing tests: add project_id=_PROJECT_ID_INT_SEMVERTAG to Settings() calls, update --project-id integration test to use mock-served project id 999, update project_id_missing assertion to match new validator message, add ioc test for _build_gitlab_client coverage

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

…_unprocessable

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

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

- ioc.py: add github_client, github_provider, current_provider factories
  mirroring the gitlab pattern; SemvertagUseCase now consumes
  current_provider which dispatches on settings.provider
- __main__.py: add --provider, --repo, --github-endpoint flags;
  --token routes to the active provider via two-pass apply_cli_overlay;
  MAIN_APP help string refreshed to "GitLab and GitHub repos"
- tests/unit/test_ioc.py: add resolution tests for both provider paths
- tests/integration/test_cli_main_verb.py: add --provider github smoke
  tests + GITHUB_ACTIONS auto-detection round-trip
- tests/integration/test_cli_errors.py: minimal fix for cascading
  settings validator
- docs/providers/github.md: new — auth, env vars, inline GHA workflow
  recipe, troubleshooting (parallel to docs/providers/gitlab.md)
- mkdocs.yml: add GitHub Actions to nav
- README.md: hero updated to "GitLab or GitHub"; new "Use it in
  GitHub Actions" section with inline workflow
- pyproject.toml: description + keywords reflect dual-provider support

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

CI runs on GitHub Actions, which auto-sets GITHUB_ACTIONS=true. The new
Settings._resolve_provider validator picks that up and routes to the
github provider — breaking every integration test that mocks GitLab
endpoints (they 401 because the github auth header isn't on the
GitLab-shaped mock). Tests passed locally because neither env was set.

Fix: an autouse fixture in tests/conftest.py monkeypatch.delenv's both
CI markers + SEMVERTAG_PROVIDER + PROVIDER before every test runs.
Tests that exercise auto-detection still set them explicitly.

Verified locally with both GITHUB_ACTIONS=true and GITLAB_CI=true
prefixed to just test — 417 pass under both.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

…er markers

Previous fix only stripped GITHUB_ACTIONS / GITLAB_CI / SEMVERTAG_PROVIDER /
PROVIDER. But GitHub Actions also auto-exports GITHUB_REPOSITORY (aliased into
Settings.repo) and GITHUB_TOKEN (aliased into Settings.github.token), so
test_provider_github_requires_repo silently failed in CI because repo was
populated by the runner's env.

Extract the full alias list as _HOST_CI_ENV_VARS and strip everything:
provider markers, repo/project identifiers, token aliases, endpoint overrides.

Verified locally with GITHUB_ACTIONS=true GITHUB_REPOSITORY=owner/repo
GITHUB_TOKEN=ghp_xxx CI_PROJECT_ID=999 CI_JOB_TOKEN=glpat-xxx just test —
417 pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>