Test-time neural memory demo

No vector DB, no lookup table: read() runs the actual fast weights W, produced by the surprise/momentum/forget update rule, fresh on every click. The memory stores BOTH class and dominant color per image, so a question about either one has real information behind it.

1. New sequence streams fresh images into the memory.
2. Pick a picture number other than the last one -- the VLM below only ever sees the most recent photo, never the earlier ones.
3. Ask (try the extra-detail box with e.g. what color was it?) and compare: without the memory hint the VLM has no way to know; with it, the answer comes from mem.read(), not from vision or fabrication.