Problem
Users have existing skills in ~/.agents/skills or ./.agents/skills (common pattern across many agents, also default install path for skills.sh). Reasonix currently doesn't recognize them, forcing manual reconfiguration.

Proposed change
Add support to load skills from:

• ~/.agents/skills/
• ./.agents/skills/

Alternatives considered

• Symlinking into current skill dir – works but fragile and per-machine.
• Custom env var – adds friction, no migration benefit.

Scope check

• This belongs in core reasonix (not better as a separate npm package)
• I've read CLAUDE.md and CONTRIBUTING.md