fix(crypto): bound public key batch lookups

[aiirvizionz]

Summary

• cap authenticated public-key batch requests at 100 IDs
• reject non-string and blank IDs
• trim and deduplicate IDs before service-role lookups

Fixes #228.

Validation

• git diff --check
• Targeted Vitest coverage added, but the local runner fails during config loading because @vitejs/plugin-react imports the non-exported vite/internal subpath. No test cases executed due to that pre-existing dependency mismatch.