Prepare CLI v0.1.3 release

[kopachlager]

What changed

• keep one timeout active across URL validation, fetch, redirects, response-body streaming, truncation, and cleanup
• add coverage for unresolved fetches, stalled bodies, normal streams, redirect revalidation, truncation cancellation, and timer cleanup
• prepare package and lockfile version 0.1.3
• update all reusable GitHub Actions examples to pin @prerenderbuddy/cli@0.1.3
• make --text-ratio-threshold explicitly compare-only and reject unsupported command usage
• verify compatibility aliases remain in JSON while duplicate human findings stay suppressed
• add release-workflow consistency tests

Compatibility

• command names, Node 20 support, JSON issue arrays, and exit-code semantics are preserved
• no runtime dependencies, browser rendering, telemetry, authentication, or hosted-service API calls were added

Validation

• 55 tests passing
• Node native coverage: 99.21% lines, 93.60% branches, 94.52% functions
• supplemental c8: 98.59% statements
• npm run check
• npm run pack:check
• npm run demo:fixture
• npm audit --omit=dev (0 vulnerabilities)
• packed tarball binary, exports, allowlist, and content scan verified
• git diff --check

Release note

This PR prepares v0.1.3 but does not create a GitHub release or publish npm.