Add minimal Claude Code skill discovery bridge

[colmarius]

Summary

This is the minimal Claude Code project-skill discovery fix for the issue described in #4, without taking on the broader registry/frontmatter/sync-local scope from that PR.

• Keep .agents/skills/ as the source of truth
• When .claude/ already exists, link each dot-agents skill directory into .claude/skills/
• Use directory symlinks so supporting files such as references/ remain available
• Preserve user-owned Claude Code skill directories and symlinks
• Remove stale dot-agents-managed symlinks on sync and uninstall
• Prepare release notes/version for v0.2.0
• Update README, Quickstart, docs, and site copy for the Claude Code behavior

Related: #4
Fixes the Claude Code native discovery problem described in #4.

Why this shape

Claude Code discovers project skills at .claude/skills/<skill>/SKILL.md, while dot-agents installs skills at .agents/skills/<skill>/SKILL.md. This PR only bridges that path mismatch. It intentionally does not add a skill registry, extra skill frontmatter fields, or a separate sync-local workflow.

Verification

• ./scripts/test.sh — lint, ShellCheck, and 56 Bats tests pass
• ./scripts/release.sh --dry-run — resolves v0.2.0 and extracts the intended changelog notes
• Manual claude CLI validation in isolated temp folders:
  • control folder without symlinks: /sample-skill returned unknown command
  • installed temp project with symlinks: /sample-skill executed and returned SAMPLE_SKILL_LOADED
  • verified .claude/skills/ralph/references/progress-format.md is reachable through the directory symlink

Release

After merge to main, publish with:

./scripts/release.sh --push