Convert a repo to the agentcanon convention

Run from the root of the repo to convert. Target state:

AGENTS.md            the real agent instructions
CLAUDE.md            symlink -> AGENTS.md
.agents/skills/      the repo's real skills
.claude/skills       symlink -> ../.agents/skills

Nothing is moved, merged, or deleted until the user approves the plan in step 2. Step 1 is read-only.

1. Inspect