CNCF .project/ spec drift: repositories items now RepositoryEntry objects

[mlieberman85]

The nightly-canary test_upstream_spec_unchanged (feature 030) fires on the current CNCF .project/ spec. Upstream commit cncf/automation@bd7fec94 (2026-08-21) added:

feat: add RepositoryEntry type with tags and primary fields

Our mapper at packages/darnit/src/darnit/context/dot_project.py:262 still declares repositories: list[str], and the reader at line 614 does data.get(\"repositories\", []) assuming string items. That is now schema-incompatible with the new upstream list[RepositoryEntry] shape.

Drift

• Tracked hash: 860df23e...
• Current hash: afa3d179...
• Diff: RepositoryEntry type added; repositories field's item type went from string to RepositoryEntry.

Impact

• Existing .project/project.yaml files with plain-string repositories still parse (backward-compat via mapper).
• New-shape .project/project.yaml files (using the RepositoryEntry object form) will silently degrade -- the string coercion will produce a truncated / stringified value that the mapper feeds downstream. Nothing crashes today; the tags and primary metadata are just lost.

Fix (feature-030 style)

1. Add RepositoryEntry dataclass to dot_project.py mirroring the upstream fields.
2. Change ProjectConfig.repositories to list[str | RepositoryEntry] (or normalize on read).
3. Update the mapper's downstream consumers to handle the object form.
4. Bump DOT_PROJECT_SPEC_VERSION.
5. Update the tracked hash: uv run pytest tests/darnit/context/test_dot_project_upstream.py -v --update-hash.

Side effect noted separately
The -m integration filter in .github/workflows/ci.yml:44 is picking up this test even though it's marked @pytest.mark.upstream, because tests/darnit/parity/tier1/conftest.py:32's pytest_collection_modifyitems applies the integration marker to every collected item (not just tier1's own tests). That's why unrelated PRs (e.g., #384) are blocked by this canary. Worth constraining that hook to items under its own conftest scope; can file separately if desired.

Runbook: specs/030-dot-project-spec-sync/quickstart.md.