chore: pin ty check execution

[vienneraphael]

Summary

• add ty to the project dev dependency flow so it is resolved through uv.lock
• run the local ty-check hook via uv run --locked ty check instead of floating uvx ty check
• mark the current intentional test diagnostics with rule-specific ty ignores

Why

CI was running ty through uvx, which fetches the current published package rather than the project lockfile. That let type-checker drift break unrelated PR CI. This makes the hook deterministic and clears the diagnostics currently present on main.

Verification

• uv run --locked ty check --python=.venv/ --exclude=examples/
• uv run --locked pytest tests/test_api.py tests/test_core.py
• uv run --locked prek run -a
• $code-review review loop: no findings