[Cloudflare One] Move Traffic policies docs to Traffic controls

[7michele7]

Summary

• Moves all Traffic policies documentation to Traffic controls.
• Moves Resolver endpoints and Proxy endpoints from Networks to Traffic controls.
• Updates canonical links and permanent redirects for every legacy path.

Jira: https://jira.cfdata.org/browse/ONEUX-1326

Testing

• pnpm run check
• pnpm run build
• pnpm exec tsm bin/validate-redirects.ts
• 48 focused worker and delegation tests

Documentation checklist

• The change follows the documentation style guide.
• Jira tracks the related dashboard move.
• Every moved page has a permanent redirect.