fix: harden Pinterest harvest recovery validation

[freshtechbro]

Summary

• reject non-canonical Pinterest recovery URLs before emitting harvest recovery commands
• keep diagnostic-only inspiredesign outputs from exposing Canvas/prototype continuation artifacts
• cover inline flag parsing, direct tool diagnostics, and not-ready artifact suppression with regression tests

Tests

• npm run test -- tests/guidance-router.test.ts tests/tools-workflows.test.ts tests/providers-inspiredesign-contract.test.ts tests/providers-inspiredesign-workflow.test.ts tests/guidance-site-recipe-validation.test.ts tests/cli-workflows.test.ts
• npm run test -- tests/providers-inspiredesign-contract.test.ts
• npm run typecheck
• npm run lint
• git diff --check
• npm run build
• npm run extension:build
• npm run version:check
• npm run test:release-gate
• npx opendevbrowser --help
• npx opendevbrowser help
• npm run test