React, loaded by Ink, picks its development build unless NODE_ENV is
exactly "production". Since React 19.2 that build records a
performance.measure() entry on every render (its DevTools "Scheduler"
and "Components" tracks), and Node keeps user-timing marks and measures
in a process-wide buffer that nothing ever trims. The interactive
dashboard re-renders on every progress tick and refresh, so the buffer
grows by roughly 700 entries a minute; after a few days the heap hits
V8's 4 GB default and the process aborts with "Ineffective mark-compacts
near heap limit ... JavaScript heap out of memory".
The launcher (dist/cli.js, the entry every client spawns) now defaults
NODE_ENV to "production" before importing main.js, which selects the
build that records nothing; an explicit NODE_ENV still wins. For that
explicit case, a small guard drops the user-timing buffer every 30 s for
the lifetime of each Ink UI (dashboard, sessions, context, compare).
codeburn records no marks or measures of its own, so nothing is lost.
Tests spawn the real launcher against a stub main.js to pin the default,
and drive a ticking Ink app in a child Node process to show the
development build's backlog, the production build's absence of one, and
the guard keeping it bounded.
