fix(cli): make skills update work with npm 11

[miguel-heygen]

Summary

hyperframes skills update can install and remove skills again under npm 11. npm 11 no longer reliably infers the package behind nested npx skills calls, which previously ended with skills: not found; explicitly selecting the skills package preserves the existing command behavior across Linux, macOS, and Windows.

Test plan

• bun run --cwd packages/cli test src/commands/skills.test.ts — 33 passed
• bun run --cwd packages/cli test — 1,747 passed, 2 skipped
• bun run --cwd packages/cli typecheck
• bun run build
• Isolated Node 26.5.0 / npm 11.18.0 smoke: built CLI installed general-video plus its core skills and exited 0

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