Add RankParse to SEO tools registry (#304)

RankParse is an agent-friendly SEO data API offering backlinks, domain
authority, tech stack, and on-page metadata at credit-based pricing.

- New integration guide: tools/integrations/rankparse.md
- New CLI wrapper: tools/clis/rankparse.js
- Registry entry under SEO category (API + MCP + CLI)

tools/REGISTRY.md

@@ -26,6 +26,7 @@ Quick reference for AI agents to discover tool capabilities and integration meth
 | ahrefs | SEO | ✓ | - | [✓](clis/ahrefs.js) | - | [ahrefs.md](integrations/ahrefs.md) |
 | dataforseo | SEO | ✓ | - | [✓](clis/dataforseo.js) | ✓ | [dataforseo.md](integrations/dataforseo.md) |
 | keywords-everywhere | SEO | ✓ | - | [✓](clis/keywords-everywhere.js) | - | [keywords-everywhere.md](integrations/keywords-everywhere.md) |
+| rankparse | SEO | ✓ | ✓ | [✓](clis/rankparse.js) | - | [rankparse.md](integrations/rankparse.md) |
 | clearbit | Data Enrichment | ✓ | - | [✓](clis/clearbit.js) | ✓ | [clearbit.md](integrations/clearbit.md) |
 | apollo | Data Enrichment | ✓ | - | [✓](clis/apollo.js) | - | [apollo.md](integrations/apollo.md) |
 | zoominfo | Data Enrichment | ✓ | ✓ | [✓](clis/zoominfo.js) | - | [zoominfo.md](integrations/zoominfo.md) |
@@ -127,8 +128,9 @@ Search engine optimization tools for keyword research, rank tracking, and site a
 | **ahrefs** | Backlink analysis, content research | Best for links |
 | **dataforseo** | SERP tracking, backlinks, on-page audits | Comprehensive API |
 | **keywords-everywhere** | Quick keyword research, traffic estimates | Credit-based |
+| **rankparse** | Cheap, agent-friendly backlinks + domain data | Credit-based, MCP available |
 
-**Agent recommendation**: Google Search Console is essential (free). Add Semrush or Ahrefs for competitive research. DataForSEO for programmatic SERP data. Keywords Everywhere for quick keyword lookups.
+**Agent recommendation**: Google Search Console is essential (free). Add Semrush or Ahrefs for competitive research. DataForSEO for programmatic SERP data. Keywords Everywhere for quick keyword lookups. RankParse for agent workflows where per-call cost matters — backlinks, domain authority, and tech stack at a fraction of enterprise pricing.
 
 ### CRM