* fix(render): glyph surgery so Spleen 5x8 K no longer reads as H
The stock Spleen K was H with one crossbar pixel removed (Hamming 1), the
worst confusable pair in the atlas. Because the API downscales images and the
model infers rather than scans, that difference vanishes and K is silently
misread as H - with no signal of uncertainty.
gen-atlas.ts now repaints K with a diagonal-legged bitmap: Hamming 8 from H,
and >=6 from every other ASCII glyph. Scoped to the narrow Spleen 5x8 primary
cell, so the JetBrains-Mono and CJK-fallback atlases are untouched. Zero
token-cost change - the glyph occupies the same 5x8 box.
Guarded by a regression test asserting no alphanumeric pair sits below
Hamming 2. Reproduce with: npx tsx eval/glyph-matrix/demo-glyph.mts
Closes the "optional glyph surgery" item in the 2026-07-01 legibility audit.
Holds the glyph cell at prod 5x8 and varies ONLY render style
(prod/onebit/color/grid/cgrid) at identical pixel dims => identical
image-token cost. Answers what the size sweep could not: at fixed cost,
does any style beat the ~10% exact-read baseline? Same content, grader,
and claude-CLI read method as eval/glyph-matrix/sweep.
- Remove eval/corpus/{sessions,text-blocks}.json from the repo — they are real captured transcripts (file paths, project names, message content). gitignore eval/corpus/; local copies kept for the eval scripts.
- gen_sweep.mjs: replace a hardcoded /Users/<name> absolute import with a relative path.
- README: 'holds ~92k readable chars' -> 'up to ~92k chars' (don't overclaim legibility at the new page density).
- CHANGELOG: note OCR legibility at the larger page size is not independently re-eval'd.
- applicability: isPxpipeSupportedModel reads PXPIPE_MODELS (comma-sep,
default claude-fable-5 only) and strips bracket/variant tags like [1m];
Opus becomes opt-in with no code change. Default behavior unchanged.
- FINDINGS: Opus 4.8 re-test - arithmetic 98/100 (-2pp), verbatim 6/15
(was 93/100, 0/15): improved but still taxed -> default stays Fable-only.
- FINDINGS + eval/glyph-matrix/sweep: root cause of the read tax is per-glyph
RESOLUTION, not font shape (confusions scale with px and vanish by 10x16).
Opus needs ~4x glyph area to read reliably; the 1568px ceiling makes that
break-even, so there is no profitable Opus operating point.
- FINDINGS.md: dated 2026-06-12 entry logging in-the-wild verbatim
misreads (7/10 exact, ~3.3% per-char, 2/3 silent) alongside flawless
gist-tier recall in the same session. Explicitly anecdotal, n=1,
non-reproducible — motivation only.
- eval/glyph-matrix/PLAN.md: public plan for the paused confusion-matrix
experiment (Task #7) so the pending work is visible outside README,
per the measured-numbers-only README rule.
dhruvraajeev