fix(evaluators): satisfy budget package-local checks

[lan17]

Summary

• remove the quoted self-type annotation in the budget config validator so the package-local Ruff pass is clean
• tighten token extraction typing in the budget evaluator so parsed token counts are guaranteed to be integers
• narrow model_path before calling the path extractor so package-local mypy passes cleanly

Why

PR 188 left the contrib budget package with pre-existing local check failures in its source. This change is intentionally narrow and keeps the existing package normalization work from feature/contrib-normalize intact while making make -C evaluators/contrib/budget check pass.

Validation

• make -C evaluators/contrib/budget check

Design Context

• Shared design doc and implementation plan: https://gist.github.com/lan17/823617097f4b7e9f4ff717979de7dba4

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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[lan17]

Superseded by #193, which rolls up this reviewed stack into one PR while preserving the logical commit boundaries for review.