v5.0.1 — Platform-neutral repositioning: renamed to humanities-writing-companion

Docs and metadata only — no skill content changed.

• Repository renamed: claude-skill-humanities-writing-companion → humanities-writing-companion (GitHub redirects all old URLs). Every hardcoded repository URL updated: READMEs, CITATION.cff, .zenodo.json, docs/, issue-template config, and the citation-verify.py User-Agent.
• Positioning de-branded from Claude: the skill is written in the open Agent Skills (SKILL.md) format and is not Claude-only. Updated accordingly: README taglines and format badge, citation titles ("A Claude Skill…" → "An Agent Skill…") in CITATION.cff / .zenodo.json / README BibTeX, the claude-skill keyword (→ agent-skill), the GitHub repo description, and CONTRIBUTING's entry-point list. New "Other agents (open SKILL.md format)" install note in both READMEs. Factual Claude Code / claude.ai / Agent SDK install instructions are retained.

Full details in CHANGELOG.md.