Records of the editor-lag deep-dive: local root-cause analysis (renderer
main-thread saturation, console DOM growth, three marker leaks, .line
transition churn, Electron 12 ceiling, thermal state) and the companion
web-research report on the 2026 TidalCycles editor ecosystem (uzu/Codeberg
migration, upstream issue #229, vim/VSCode/browser alternatives, no prior
art for Pulsar forks). Fixes landed in the pulsar-tidalcycles fork, branch
perf/event-highlighter, commit 6e9f374.