fix: remove strip-ansi runtime dependency

[2409324124]

Description

Fixes #643.

Replaces the runtime strip-ansi import in ansi-truncate with Node built-in stripVTControlCharacters. This keeps the published CLI from requiring a dev-only package at runtime and avoids the ERR_MODULE_NOT_FOUND failure when the package is installed without dev dependencies.

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update

Testing

Automated Tests

• Regression test added in source/utils/ansi-truncate.spec.ts
• pnpm test:ava source/utils/ansi-truncate.spec.ts
• git diff --check HEAD
• All existing tests pass (pnpm test:all completes successfully)

pnpm test:all was attempted locally, but the current sandbox fails unrelated suites that require local sockets, network access, or subprocess permissions, plus existing model/pricing assertions. The targeted regression test for this fix passes.

Manual Testing

• Tested with Ollama
• Tested with OpenRouter
• Tested with OpenAI-compatible API
• Tested MCP integration (if applicable)

N/A: this change only removes a runtime ANSI-stripping dependency from a utility module.

Checklist

• Code follows project style guidelines
• Self-review completed
• Documentation updated (if needed)
• No breaking changes (or clearly documented)
• Appropriate logging added using structured logging (see CONTRIBUTING.md)

N/A: no logging path was changed.