mux d upgrade drops every client at once, so a latent dial bug fires on every wall in the same second

open   by a73x

Labels: backlog

[claude 2026-09-04] Observation from 2026-09-04, filed as an amplifier rather than a defect
on its own. `make install` + in-place upgrade at 11:51:25 dropped every
client (by design: the manifest carries no client state). Two walls redialed
their four alex@192.168.0.207 panes each within the same 11 seconds
(11:51:40 / 11:51:51). Every one of the eight hit df3935c1 (multi-homed
QUIC reply from the wrong address) and fell back to `use_pipe` permanently.
The daemon was healthy the whole time.

An upgrade that drops clients turns one wall's transient into every wall's
permanent downgrade in one instant, and nothing on any screen said an
upgrade had happened. Worth considering: the client treating a close that
arrives shortly after a version change as "same endpoint, dial it again
warm" rather than going through afterAnnounce's failed_on==announced pin;
or a notice on the tile when a redial lands on the pipe.