Add --install-skill for agent skills and Cursor rules

[muhajirdev]

Summary

Adds --install-skill so agents get persistent guidance on when and how to use agentmap before falling back to grep.

• --install-skill CLI flag with --platform (claude, cursor, agents, all), --project / --global, and --dry-run
• Ships skills/SKILL.md (Claude / agents skill) and skills/cursor-rule.mdc (Cursor always-on rule)
• skills/install.mjs handles atomic writes and version stamping
• Tests and README docs included

Install destinations

Platform	Path
claude	.claude/skills/agentmap/SKILL.md (or ~/.claude/... with --global)
agents	.agents/skills/agentmap/SKILL.md
cursor	.cursor/rules/agentmap.mdc (project only)

Usage

agentmap --install-skill                    # all platforms, project scope
agentmap --install-skill --platform cursor  # Cursor rule only
agentmap --install-skill --global --platform claude
agentmap --install-skill --dry-run

Motivation

Without a skill or rule, coding agents default to grep even when agentmap --find or --relates would be faster and more precise. This copies packaged agent guidance into the standard skill/rule locations each platform already reads.

Test plan

• npm test — 127/127 pass (3 new install-skill tests)
• agentmap --install-skill --dry-run in a sample repo
• agentmap --install-skill --platform cursor and confirm .cursor/rules/agentmap.mdc is created
• Verify Cursor picks up the always-on rule in a real session

[raymondchins]

Thanks @muhajirdev! Solid addition — extends the agent-loop guidance to Cursor / Codex / OpenCode, and the security side is clean (whitelisted platforms, fixed literal path segments, atomic writes, no traversal).

I pushed one commit to your branch with two fixes:

• The .agentmap_version assertion was hardcoded to /0\.6\.0/ and would have gone red after merging onto main (now 0.6.1), since install.mjs reads the version live from package.json — changed the test to derive the expected version from package.json.
• Moved the installer to a lazy await import() inside the --install-skill branch and read VERSION inside installSkill(), so the warm --any / --find hot path never loads it (matches the existing lazy ts-morph / lazy mcp.mjs discipline).

Full suite green (127/127). Mark it Ready for review whenever you're happy and I'll merge. 🙏

(Optional, non-blocking follow-ups: a --global-scope test and an unknown---platform error-path test.)