fix: make CI example fail partial and unscored runs

[rudycelekli]

Problem

The shipped ifixai/examples/ci_check.py formats overall_score as a percentage before checking whether a run is gradeable. When the score is None (the normal result for an unscored run), the example crashes with TypeError instead of explaining the failure. A partial run can also return a high provisional score and satisfy all thresholds, causing this CI example to exit 0 despite the run being incomplete. The main CLI explicitly rejects partial runs.

Change

• Print n/a for unavailable overall scores and grades, and fail with an actionable message.
• Fail partial runs regardless of provisional numeric scores, including the abort reason when available.
• Keep complete scored runs on their existing threshold path.

Verification

• Before the change, both new failure cases failed: an exception for null overall, and exit 0 for partial. Afterward, all three focused tests pass, including a complete passing control.
• uvx ruff check on changed files, uvx bandit -r ifixai -ll -q, ifixai validate, and git diff --check pass.

No provider, fixture, or inspection behavior changes.

[mraalegend]

Please U need a guide

[mraalegend]

Please I need video guide

[rudycelekli]

Here is a short written walkthrough for this PR:

1. Check out this PR and install the development dependencies as described in CONTRIBUTING.md (pip install -e ".[dev]").
2. Run python -m pytest ifixai/tests/test_ci_check_unscored.py -q. The tests use a local fixture rather than a live provider, so they require no API key or paid calls.
3. The two failure cases are an unavailable overall score and a partial run despite a high score. Both must return exit code 1. A complete, scored run that meets the thresholds still returns 0.

The user-facing change is that an incomplete evaluation can no longer let CI pass, and an unavailable score prints n/a rather than crashing during formatting. This is a written reproduction, not a video guide.

[stefyi-4355]

lgtm