v0.7.8 - Cloudflare single-redirect management

Adds cf_list_redirects (read), cf_create_redirect and cf_delete_redirect (gated behind SEO_MCP_ALLOW_DESTRUCTIVE) for managing single (dynamic) redirects at the Cloudflare edge - e.g. a 301 for a renamed URL. Creates pre-flight the target (no redirecting to a dead URL), refuse self-loops and duplicate sources, advise 301-over-302, and support dry_run. New token scope: Zone > Single Redirect > Edit. 52 -> 55 tools (13 prompts unchanged). Account-level Bulk Redirects follow in 0.7.9. See CHANGELOG.md.