docs: show npx form for the sg-material commands

[ayden94]

Summary

The Material v2 block shows only the global-install form (sg-material ...). That form is not reachable through npx:

$ npx stylegallery sg-material discover
{"ok": false, "failures": [{"code": "command_unknown", "message": "unknown command sg-material", "path": "command"}]}

The working form is npx --package stylegallery sg-material ..., which matches the npx --package stylegallery stylegallery-mcp form already used in the MCP section above.

Changes

• README.md only: npx forms for discover, search --paths-only, and context, plus one sentence noting the global-install form.

Evidence

Verified against the published package (stylegallery@0.1.7):

$ npx --package stylegallery sg-material discover
{"ok": true, "operation": "material-discover", ...}

Local validation on origin/main (70fde7d):

node scripts/validate-okf.mjs --json    -> "ok": true, "failures": []
node scripts/validate-links.mjs --json  -> "ok": true, "failures": []
node scripts/validate-ia.mjs --json     -> "ok": true, "failures": []

No validator changes, no generated artifacts touched.

[changeroa]

Approved. Thank you @ayden94 for filling this setup gap.

Verified all three documented npx commands against the published package: discover, search --paths-only, and bounded context all succeed.

The change is correctly scoped to README guidance; no runtime refactor is needed. The combined landing also passes OKF, links, IA, governance, and the full material test suite. README is admitted material, so its changed bytes require a registry refresh: I reproduced material_source_hash_mismatch and regenerated the registry in a separate maintainer commit. Your original commit and authorship are preserved on land/pr-45-46. Full CI will be checked before advancing main.

consumer_reference: consumer-reference/agent-native/registry.json

[changeroa]

Landed on main with your original commit and authorship preserved. Thanks @ayden94 for improving Material setup documentation in #45.

The only maintainer addition is the generated README registry refresh in 2a9ae14, required because README is admitted material. All six validation jobs passed on that exact commit: https://github.com/changeroa/StyleGallery/actions/runs/35808591172

This is a repository documentation update; no new npm release was published.