ssb-viewer holds one muxrpc handle captured in a closure and has no
reconnect path. When sbot is OOM-killed and restarted by run-server.sh,
the viewer kept port 8807 open while holding a dead connection and never
answered again -- the silent wedge.
Listen for muxrpc closed and exit(1) so the while-loop in
run-ssb-viewer.sh restarts with a fresh connection. Also poll whoami to
catch half-open connections where closed never fires.
Verified: killing sbot now self-heals in ~4s instead of hanging.
ops
cel