- concepts/streaming.md: remove '# Streaming + chunking'.
- reference/session-management-compaction.md: remove Title Case H1
'# Session Management & Compaction (Deep Dive)'.
- plugins/voice-call.md: remove '# Voice Call (plugin)'.
CLI pages keep their command-formatted body H1s since that is the repo
convention and the formatting is not expressible in frontmatter.