test: pin cwd for deep-coverage CLI fixtures

[Daniel Meppiel (danielmeppiel)]

Description

tests/integration/test_commands_deep_coverage.py passed the project to the CLI through obj={"cwd": ...}, which no command reads, so apm deps list ran in whatever directory the xdist worker was left in. When an earlier test had removed that directory, deps list exited 1 ([x] Error listing dependencies: [Errno 2] No such file or directory). This failed test_deps_list_no_apm_modules on macOS arm64 in the v0.34.0 tag run (39231396347) and in the 2026-10-14 nightly.

The project_with_deps / project_no_deps fixtures now monkeypatch.chdir into the project, so every test in the file runs against the project it builds.

Issue and approved scope

Issue: N/A -- maintainer-directed release-gate repair for v0.34.0 (#3250); follow-up to #3251, #3253, #3262.

Human scope-approval comment: Daniel Meppiel (@danielmeppiel) directed in-session to bypass-merge release-gate fixes "until we can guarantee the release will go through".

Does this PR complete the issue, or what remains? Completes this flake.

Type of change

• Bug fix
• New feature
• Documentation
• Maintenance / refactor

Testing

• Tested locally

• All existing tests pass

• Added tests for new functionality (if applicable)

• Reproduced the cause: apm deps list from a deleted cwd -> exit 1 with the error above.

• uv run --extra dev pytest tests/integration/test_commands_deep_coverage.py -- 28 passed.

• ruff check / ruff format --check on the file -- pass.

Spec conformance (OpenAPM v0.1)

• Spec edit: docs/src/content/docs/specs/openapm-v0.1.md updated
  (new/changed <a id="req-XXX"></a> anchor + prose + Appendix C
  row).
• Manifest edit: docs/src/content/docs/specs/manifests/openapm-v0.1.requirements.yml
  updated.
• Test edit: a @pytest.mark.req("req-XXX") test under
  tests/spec_conformance/ added or extended.
• CONFORMANCE.{md,json} regenerated via
  uv run --extra dev python -m tests.spec_conformance.gen_statement
  and committed.
• N/A -- this PR does not change OpenAPM-observable behaviour.

[Copilot]

🟢 Approval recommended

The narrow fixture changes correctly isolate CLI execution and restore the working directory automatically, with no unresolved findings.

No open issues 🎉

What changed in this PR

Fixes working-directory isolation in deep-coverage CLI tests, addressing a release-gate flake without changing production behavior.

Changes:

• Both project fixtures enter their temporary project directory using monkeypatch.chdir.
• Comments explain why passing obj["cwd"] does not select the CLI project.

File	Description
tests/​integration/​test_commands_deep_coverage.py	Pins both project fixtures to the intended working directory.

_{Review effort: Balanced}