docs: sync documentation with actual repo state; adapt for Gitea

- Remove all .github references (removed in 6c644dd but docs still referenced)
- Rewrite review-pr skill to use Gitea API instead of gh CLI
- Add gitea-pr.sh helper for Gitea API calls (view/diff/files/comments)
- Update project structure tree: add scripts/, .woodpecker.yml, ci-cd.md,
  status-update-checklist.md, commit-docs-reminder.sh, RESEARCH-SDD-TOOLS.md
- Fix skills count 14 → 15 (add create-skill to DOCS.md)
- Remove .github references from CONTRIBUTING.md, SECURITY.md, init-project
- Add GITEA_TOKEN to .env.example
- Update CI/CD placeholder in RECOMMENDATIONS.md to Woodpecker

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

SECURITY.md

@@ -7,7 +7,6 @@ If you discover a security vulnerability in this project, please report it respo
 **Do not open a public issue.** Instead:
 
 1. Email: **[your-security-email@example.com]** (replace with your contact)
-2. Or use [GitHub private vulnerability reporting](https://docs.github.com/en/code-security/security-advisories/guidance-on-reporting-and-writing-information-about-vulnerabilities/privately-reporting-a-security-vulnerability) if enabled on this repository.
 
 ### What to include