feat(agent-ready): recommend stack-specific project skills

[dgalarza]

Summary

• detect supported frameworks, services, and infrastructure using strong project signals
• recommend curated skills for React, React Native/Expo, Angular, Svelte, Mastra, FastAPI, Laravel, Supabase, Stripe, Cloudflare Workers, and Terraform
• offer Anthropic frontend design and Vercel web design guidance in a separate optional UI tier
• check project-local installations and require explicit confirmation before installing with npx skills add
• document the recommendation catalog and bump agent-ready to 1.4.0

Validation

• python3 .agents/skills/skill-creator/scripts/quick_validate.py plugins/agent-ready/skills/agent-ready
• catalog command/name checks for all 13 skills
• plugin and marketplace JSON parsing/version-sync check
• git diff --check