Harden OrgX MCP tool compatibility

[hopeatina]

Summary

• route legacy orgx_create_entity type=artifact calls through durable artifact registration
• normalize legacy workstream status: in_progress updates to canonical active
• return explicit auth guidance for orgx_proof_status 401 responses
• isolate onboarding pairing tests from local authenticated OpenClaw/OrgX config

Verification

• npm run typecheck
• npm run build:core && npm run test:file -- tests/http/onboarding-pairing-timeout.test.mjs tests/tools/core-tools-register-artifact.test.mjs tests/tools/core-tools-api-compat.test.mjs tests/tools/core-tools-proof-status.test.mjs
• npm run test:hooks
• npm run build
• git diff --check