content: remove deprecated Continue integration

[TeoSlayer]

Continue has joined Cursor and its repository is read-only and no longer actively maintained.

• removes the Continue integration article and listing
• removes Continue from current MCP and managed-harness coverage
• permanently redirects the old article URL to the general MCP setup guide
• teaches the site integrity audit to exclude noindex redirect documents from page-level SEO checks

Validation:

• npm run build
• npm run check:site
• npm run check:plain
• git diff --check

[github-actions]

🚀 Preview deployed to Cloudflare Pages

• Commit deploy URL: https://1bf30571.pilotprotocol.pages.dev
• Branch alias: https://codex/remove-deprecated-continue.pilotprotocol.pages.dev (may take ~30s to propagate)
• Commit: 13f5b51e926a8f24351b3ad198af2f93e9ef121a