chore: remove pyright configuration and use ty instead

[GeorgePearse]

Removes all pyright configuration files and references since the project has migrated to using ty for type checking.

Changes

• ❌ Deleted pyrightconfig.json (pyright-specific config file)
• 🔄 Removed pyright hook from .pre-commit-config.yaml (lines 36-40)
• ✨ Replaced pyright step with ty in .github/workflows/test-coverage.yml

Rationale

The project now uses ty (the new strict type checker) as the primary type checking tool. Pyright was previously used but is no longer needed since:

• [tool.ty] configuration is already in pyproject.toml
• ty provides stricter type checking aligned with project standards
• Removing unused tools simplifies the toolchain

Type Checking Pipeline

The workflow now uses:

uv run ty check

Instead of:

pyright

Testing

✅ All 231 tests pass
✅ Pre-commit hooks pass
✅ No functional changes, only configuration cleanup

Notes

• The continue-on-error: true flag is kept so CI doesn't fail on type warnings
• ty validation is more strict than pyright was, pre-existing issues remain
• No dependencies removed (pyright not in pyproject.toml)

[github-actions]

Coverage report

This PR does not seem to contain any modification to coverable code.