generateColoredAsciiFlood emitted a trailing \r\n after its final cell, so a
flood whose last line lands on the bottom row scrolled the screen. In the
alt-buffer repro this destroyed the pinned header row in the BUFFER, making
the 255/255 signature diff a content change, not renderer corruption. The
single-terminal merge path is actually healthy: with the scroll removed the
same 30-chunk merge-heavy workload renders the header with zero drift.
- generateColoredAsciiFlood: no linefeed after the final cell
- WebglReproExperiment: now a green guard; asserts row-1 buffer text first so
a content bug can never masquerade as corruption again
- WebglVisual: accurate comments; erase rewritten lines so leftover prefill
text doesn't look like corruption
- WebglSingleTermStress: replace stale EXPECTED-RED comment (test passes)
Anthony Kim