An upload sends its file name next to the raw bytes, and the server keeps
it in a sidecar next to the content-addressed file. Both pickers caption
every tile and row with it, and an asset made there is named after the
file instead of "Texture" / "Font". Last upload of the same content wins.
The API's own set_error_handler ignores error_reporting(), so @-silenced
warnings still throw: a missing sidecar took the whole listing down with a
500. Existence is checked instead of suppressed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
