staleButtonServer increments its per-method map from the HTTP handler, which
httptest runs on one goroutine per connection. #6491's
TestAdminListReadersShareTheWriterLock is the first test to reach it from
several goroutines at once, so CI's race job flagged the helper's map rather
than the code under test.
Tapping an old get_clients_for_* inline keyboard re-fetched the inbound
after the keyboard lookup, discarding the error; if the row vanished
between the two reads, the second GetInbound returned nil and
inbound.Remark panicked. The callback handler runs on a bare goroutine
with no recover(), so that panic killed the whole panel process.
Fetch the inbound once in a shared chooseInboundClient helper that
answers an error callback on a missing row, and pass the row down to
getInboundClientsFor instead of re-reading the DB, removing the
between-reads window. Route all three OnReceive handler paths through a
recover() barrier so no handler panic can take down the process, and log
the GetInbound failure instead of silently swallowing it.
Sanaei