fix: gate direct url research evidence

[freshtechbro]

Summary

• Treat direct URL research search records as provisional candidates, including community, web, social, and YouTube-specific search URL paths.
• Require destination fetch evidence before synthesis so no-link direct URL records cannot become final research evidence.
• Reject Google static, analytics, tag manager, ad, syndication, and doubleclick hosts from follow-up research destinations.

Review and test loop

• RepoPrompt review found direct URL no-link evidence gating issue.
• RepoPrompt rereview found YouTube-specific search URL and Google analytics host gaps, both fixed.
• Final RepoPrompt review reported no findings.

Real-world proof

• Ran an in-process research workflow against https://developer.chrome.com/docs/extensions/develop/concepts/service-workers/lifecycle.
• Artifact bundle included bundle-manifest.json, context.json, meta.json, records.json, report.md, and summary.md.
• Final records had no blocked static or analytics hosts; 10 provisional web:search:url records were rejected before synthesis.

Validation

• git diff --check
• npm run lint
• npm run typecheck
• npm run build
• npm run test -- tests/providers-workflows-branches.test.ts tests/providers-research-executor.test.ts tests/providers-traversal-url.test.ts
• npm run test: 4246 passed, 1 skipped, 97.01% branch coverage