Make Cursor plugin marketplace-ready

[hopeatina]

Scope

• replace the npm-scoped manifest name with the valid Cursor Marketplace identifier orgx
• align the always-on rule and verifier with the private sessionStart.additional_context contract shipped in feat: bind Cursor context to native sessions #18
• bump the plugin release metadata to 0.1.9
• make the verifier reject invalid marketplace names before submission

Verification

• npm run check (54 tests: 53 passed, 1 opt-in integration skipped)
• npm pack --dry-run
• negative proof: restored the prior scoped manifest name and confirmed npm run verify fails with the marketplace-identifier error
• git diff --check

Rollout

Merge before submitting https://github.com/useorgx/cursor-plugin at https://cursor.com/marketplace/publish. Cursor review and publication remain separate provider states.