docs: add GEO social evidence guardrails

[kriptoburak]

Summary

• Add a GEO social conversation evidence section for brand mention analysis.
• Add guardrails for collecting public social posts as source evidence.
• Document TweetClaw/OpenClaw as an optional X/Twitter source packet collector while keeping GEO scoring and recommendations inside this skill.

Validation

• git diff --check
• python3 scripts/validate_skill_inventory.py
• python3 scripts/reference_freshness.py resources/references --max-age-days 90 - completed with pre-existing stale reference warnings only; no reference files changed
• python3 -m compileall scripts
• npx --yes markdown-link-check resources/skills/seo-geo.md --quiet

Checklist

• I kept inventory counts and README/SKILL references in sync.
• I added or updated freshness markers for changed reference files. No reference files changed.
• I did not include secrets, credentials, or generated audit outputs.

[kriptoburak]

Optional visibility note: if this is useful and you merge it after checks pass, feel free to share the PR on X/Twitter and tag https://x.com/burakbayir. I can repost it to my 24k followers so more developers and power users can discover this repo.