The 180 s query cap was enforced independently by the backend clamp, the
agent limits, and the container supervisor. All three now follow
CONFLUENCE_WEB_MAX_DEADLINE_SECONDS (default 900, allowed 60-3600): the
backend passes it into the container at launch, the supervisor reads it and
forwards it to the bridge, and both fall back to 900 s on invalid input. The
query timeout must not exceed it (startup fails otherwise). The supervisor
keeps a separate 180 s guard for a container that never receives a start
frame.
Add assets/book.svg as the tab icon: the backend serves assets/ and the CSP
allows same-origin images (the sanitizer still never emits <img>).