chore(release): v1.6.1-aio.17

Ticket availability and publish delivery.

- #58 publishes are confirmed against the relay's NIP-01 `OK` instead of
  the send queue. A publish that never reaches a relay now leaves the row
  flagged for the sweep rather than reporting success and clearing it —
  which had silently reverted a completed repair on cfaun. Verified end
  to end on aio-demo: delivery confirmed, the no-relay failure caught
  with the relay's own diagnostic in the log, and the retry recovering
  once the relay returned.
- #59 `amount_tickets` is the remaining count; `api_ticket_create` no
  longer subtracts `sold` from it. Every event was locking itself as sold
  out at half capacity. 16 of 24 live events on aio-demo were affected,
  3 already refusing sales with stock remaining.

No schema change. Affected events start selling again on upgrade; worth
re-running an availability check per host afterwards.

config.json

@@ -1,6 +1,6 @@
 {
   "id": "events",
-  "version": "1.6.1-aio.16",
+  "version": "1.6.1-aio.17",
   "name": "Events",
   "repo": "https://git.atitlan.io/aiolabs/events",
   "short_description": "Sell and register event tickets",