Add Hermes Tweet to SkillX seed data

[kriptoburak]

Summary

• Add Hermes Tweet as a source-linked SkillX marketplace seed entry.
• Position it as the native Hermes Agent X/Twitter plugin with read-first workflows and approval-gated actions.
• Keep the listing lightweight: no vendored plugin code, no secrets, and no copied runtime assets.

Validation

• jq empty scripts/seed-data.json
• node -e required-field validation over all 5,081 seed entries
• node -e Hermes Tweet diff safety term check
• gh api repos/Xquik-dev/hermes-tweet/contents/skills/hermes-tweet/SKILL.md
• git diff --check

Notes: the repository currently has no installed dependencies in this checkout, so I did not run the full pnpm test suite for this data-only change. The repository has no top-level LICENSE file, but README documents MIT; Hermes Tweet is MIT licensed.