Basics, failure semantics on 26 vs 27, lazy collections, API across 25/26/27, preview-flag traps and a JMH read-path benchmark (jars fetched and sha1-checked, not committed).
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01TF9JWFvJSNm6HVzswzZU5a
