Add project structure documentation (AGENTS.md) and initial README files
that organize skills by bucket and invocation type (user-invoked vs
model-invoked).
Introduce three skills:
- forge-interaction: GitHub/Gitea CLI automation for issues, PRs, releases
- forge-preferences: personal forge conventions (companion to forge-interaction)
- pkm-curation: Obsidian vault curation and note management
Include reference docs for vault conventions, agent integration, and the
invocation model that separates user-only from model-reachable skills.
gitadmin