feat(cursor): migrate agents to new .agents/skills/*/SKILL.md format (#179)

[gbpnkans]

Fixes #179. Migrates the Cursor installation and conversion scripts to use the new .agents/skills/ structure and SKILL.md formats instead of the old .cursor/rules/*.mdc format.

[msitarzewski]

Hey @gbpnkans — thanks for tackling this, the Cursor format migration is something we need to do.

The approach needs to change though: the generated SKILL.md files can't be committed. All integration output in this repo is gitignored — users run convert.sh locally to generate it (see CONTRIBUTING.md).

The right fix here is updating convert_cursor() in convert.sh to output the new .agents/skills/*/SKILL.md format instead of .cursor/rules/*.mdc, and updating install_cursor() in install.sh accordingly. No committed output — just the script changes and an updated README.

Would you be up for reworking it that way?