fix: reject invalid numeric CLI options

[mikemikimike]

Summary

Validate numeric CLI options before scanning a repository so invalid thresholds cannot produce misleading reports or silently disable a CI gate.

Background

Number() converted values such as abc to NaN, while negative values were accepted. That allowed --max-tokens abc, --price -3, and --top -1 to exit successfully with nonsensical behavior.

Changes

• Reject non-finite and negative values for --price and --max-tokens.
• Require --top to be a non-negative integer.
• Require --fail-on-waste to be a finite percentage from 0 through 100.
• Match long options exactly, while retaining both separated and --option=value forms.
• Add CLI regression coverage and bump the package version to 0.1.3.

Implementation

Validation runs before repository scanning and ignore-file writes, so invalid input exits with status 2 without filesystem side effects. Existing defaults and valid scan/report behavior are unchanged.

Compatibility / Known limitations

The project remains zero-dependency and supports its existing Node.js >=18 engine range. The local environment used Node 22; the repository workflow runs the same tests on Node 20.

Tests

• npm test — 9 passed, 0 failed.
• node bin/ctxtrim.js test/fixtures/sample-repo --format json — smoke output generated successfully.
• node --check src/cli.js
• node --check bin/ctxtrim.js
• git diff --check

Issue

Closes #8