CI: fix flaky isolated_filesystem failures in functional_test

[ake2l]

Problem

Four tests_ce/functional_tests/test_cli/test_cli.py tests were failing in CI with:

AttributeError: 'CliRunner' object has no attribute 'isolated_filesystem'

All four tests use runner.isolated_filesystem() (a click.testing.CliRunner context manager). The 16 other tests in the same file — same runner = CliRunner() instance, just no isolated_filesystem call — all passed. Tests pass locally with the same pinned versions (click 8.2.1, typer 0.16.0), and every click version from 7.1.2 → 8.4.1 ships the method, so this is a CI-environment issue, not a code or version-spec issue.

Changes

1. Robust test rewrite (primary fix). Replaced runner.isolated_filesystem() with pytest's standard tmp_path + monkeypatch.chdir(tmp_path) in the 4 affected tests. Same isolation guarantee, no dependency on click's testing surface, more idiomatic.

2. Cache-key correctness. The .venv cache key in .github/workflows/main.yml hashed only pyproject.toml. Since transitive deps live in uv.lock, lock-only updates couldn't invalidate the cached venv. Updated all 9 cache key references to:

   key: ${{ runner.os }}-python-${{ hashFiles('./pyproject.toml', './uv.lock') }}

3. Diagnostic step added to functional_test that prints click/typer versions, file paths, CliRunner MRO, and hasattr(runner, 'isolated_filesystem'), plus uv pip list | grep click|typer. Leaves a trail so we can pinpoint the underlying CI env issue (likely a partial/corrupt restored .venv) without it blocking the build.

Verification

• All 20 tests in test_cli.py pass locally.
• Refactored tests use only tmp_path + monkeypatch.chdir, which doesn't depend on the broken surface area.

Follow-up

Once the diagnostic step runs in CI we'll know whether the restored .venv has the expected click version. If it turns out cache corruption is real, we should consider either dropping the cache entirely or running uv sync --frozen in each test job rather than trusting the cached .venv.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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