fix(admin): show owner identity in ownership transfers

[ctkm-aelf]

Summary

• Add owner_name and owner_email to the admin ownership inventory response using one batched users lookup for the current page.
• Show the owner's name, email, and UUID in the transfer inventory. Missing names fall back to email, and missing accounts retain the UUID.
• Keep the frontend on its existing single inventory HTTP request; no per-owner API requests are made.

Verification

• npm test -- --run src/pages/admin-ownership.test.tsx src/components/shared/ownership-transfer-dialog.test.tsx (7 passed)
• npx tsc -b --pretty false
• Targeted ESLint and Prettier checks
• cargo fmt --check --all
• cargo check -p nyxid --tests

The MongoDB integration test was compiled but not executed because this environment has no configured replica-set test database.

[github-actions]

📊 Code coverage

Component	Lines	Threshold	Status	Δ vs base
Backend (nyxid)	87.69%	73%	✅	— 0.00
Frontend (vitest)	71.45%	15%	✅	🔻 -0.01

Gate: line coverage must stay at or above the threshold. Ratchet plan (W21): Backend → 55%, CLI → 50%, Frontend → 30% by quarter end.