reading map: seven models, one library — /reading/models

The same 9,194 passages arranged by seven embedding models, switchable. Every
model's coordinates are Procrustes-aligned to nomic, without which the toggle
would be seven unrelated arrangements and the motion between them meaningless.

⚠️ The page states the NEIGHBOUR-AGREEMENT number, not the animation, and the
distinction is load-bearing. Every projection of 1024 dimensions into 3 is lossy
in a way that shapes what you see: measured directly, PCA and UMAP disagreed by
10x about whether whole books move together, each reporting its own arithmetic.
So the claim is computed on the raw embeddings where there is no projection to
be an artifact of (models share ~50% of each passage's 15 nearest neighbours),
and the picture illustrates that number rather than being the evidence for it.
The page says so in as many words.

Renderer gains setCoordinates(), driven from the existing render loop rather
than its own rAF so a morph cannot outlive the scene or run while scrolled away.
It writes through the single `xyz` buffer the nebula, signal and trace all read
from, so every layer moves together and nothing drifts out of registration.

`trace` is now optional. The banner and explorer always carry one; a comparison
payload legitimately does not — its subject is where passages MOVE between
models, not the order they were highlighted in.

Payload is split: a 44 KB manifest with everything shared, plus one ~145 KB
coordinate file per model fetched on demand. The per-node book/kind arrays are
identical across models, so carrying them seven times is waste, and eager
loading would be ~1.1 MB before first paint.

auto-build.sh now watches public/reading_*.json as ONE glob. The previous
OR-chain was subtly broken — with `-o` the `-printf` binds only to the last
clause, so earlier matches printed in a different format and the signature was
not stable. The glob also picks up future payloads without an edit.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitignore

@@ -15,6 +15,10 @@ public/reading_umap.json
 # (`export.py --explorer`, 15/0.1 plus the kind and section layers). Tracking it would dirty
 # the tree exactly as above.
 public/reading_explorer.json
+# the /reading/models comparison: a manifest plus one coordinate file per embedding model,
+# fetched on demand. Same generator, same reason they must stay untracked.
+public/reading_models.json
+public/reading_models.*.json
 .build_state
 .build.lock
 .notebooks.lock