[Flotapponnier]

every logo is revalidated on every page view, and /capital has 158 of them

Provider marks are plain files under public/, and Next serves those as
cache-control: public, max-age=0, must-revalidate unless the config says
otherwise. The config did not: the only Cache-Control rule in next.config.ts
was for /api/citable.

must-revalidate means a browser holding the whole set in its disk cache still
has to ask the server about each file before it is allowed to paint it. On
/capital that is 158 conditional requests per visit. Measured against prod
from a machine sitting next to the cdg1 edge, each 304 costs about 95 ms and
carries no bytes. The marks render as empty circles until they land, which is
what a reader sees.

Why it turned slow recently rather than gradually: the page's logo set has
been growing, and most of the growth is new. Counting the files /capital
actually references by the month each was added to the repo:

2026-05 28 files 476 KB running 28 / 476 KB
2026-06 16 89 KB 44 / 564 KB
2026-07 19 663 KB 63 / 1227 KB
2026-08 18 326 KB 81 / 1553 KB
2026-09 72 1785 KB 153 / 3338 KB

September alone doubled the file count and added more weight than the four
months before it put together. A missing cache header is harmless at eighty
images and is not at a hundred and sixty.

So /logos/* gets a day of silence and then a month of serving the cached copy
while a fresh one is fetched behind it. Deliberately not immutable: these
filenames are stable and their CONTENTS get replaced — Chainstack sent a new
mark in #2910 — so a year-long immutable cache would pin an old logo on every
returning reader. A day is short enough that a swapped mark turns up on its
own.

Verified rather than assumed, because a config header does not always win:
the same block carries a comment about /api/citable, where this layer loses
to the Cache-Control the route handler sets. Static files have no handler, so
the rule applies. Checked on a dev server:

$ curl -sI /logos/ronin.png
Cache-Control: public, max-age=86400, stale-while-revalidate=2592000

and /favicon.ico still answers no-cache, must-revalidate, so the scope is
the one intended.

This does not touch the other half of the problem, which is a separate job:
3.5 MB of marks on one page, for circles rendered at 22 pixels. 32 files are
over 30 KB and carry 69 % of the weight, ronin.png alone is 227 KB. Re-encoded
at 64 px those 158 files would be roughly 630 KB, an 82 % cut on first load.
That one rewrites binaries and wants its own PR.