Add Xquik API search skill

[kriptoburak]

Summary

• Add api-search-xquik as a source skill for Xquik-backed X/Twitter data workflows.
• Include the generated Claude plugin under dist/plugins/api-search-xquik.
• Register the generated plugin in .claude-plugin/marketplace.json.

Validation

• npm run update-marketplace
• jq empty .claude-plugin/marketplace.json dist/plugins/api-search-xquik/.claude-plugin/plugin.json
• YAML and skill frontmatter parsing for the new source and generated skill
• Source-truth endpoint check against https://xquik.com/openapi.json
• Local Markdown link validation: 4 links checked
• Scoped external link check: 5 pass, 0 fail, 0 skipped
• Changed-file Prettier check for the new Xquik files and marketplace JSON
• git diff --cached --check
• Staged diff scans for secrets, prohibited references, excluded repo names, literal escaped newlines, and unsupported private implementation details

Notes

• Full bun run format:check currently reports pre-existing generated dist/plugins/* formatting warnings outside this change. The changed Xquik files pass Prettier directly.

Duplicate Check

• Checked default-branch code search plus open and closed PRs and issues for Xquik, x-twitter-scraper, xquik.com, Xquik-dev, and X Twitter Scraper.
• Found no existing Xquik placement in this repository.