Without a catch-all handler, slack-bolt returns HTTP 404 for every
unhandled bot event (user_change, user_huddle_changed, reaction_added,
etc.) and never sends the Socket Mode ack. On active Slack workspaces
where the app is subscribed to high-volume events, this produces a
near-100% un-acked failure rate that crosses Slack's >95%/60-min
threshold and triggers automatic disabling of the app's Event
Subscriptions — silently killing all inbound event delivery.
Place a catch-all re.compile(r".*") handler AFTER the specific event
handlers so bolt's router matches those first. Truly unhandled events
are silently acked (200) and logged at DEBUG. The failure rate stays
near 0% regardless of which events the Slack app manifest subscribes to.
Fixes#6572
93102e91cf