chore(release): v1.6.8-aio.4

- #68 ticket waves never rendered in the organiser table. The chip built
  its label inline with `LNbits.utils.formatCurrency(...)`, but Vue
  resolves template expressions against the component instance, where the
  `LNbits` global is not in scope. It threw "Cannot read properties of
  undefined (reading 'utils')" and the whole v-for rendered nothing, so
  every event showed an empty wave list however many waves it had.
  Organisers could not see or edit a wave from the LNbits UI at all.

The line came in with the v1.6.8 merge: it is upstream's, and the only
`LNbits.` reference in any template here — display.vue and ticket.vue
have none. `waveSummary` now builds the label in index.js, and trims the
time off wave dates for display.

Frontend only; no Python, no schema, no migration.

Verified in a browser against a two-wave event before tagging: both
chips render with formatted currency and no TypeError.

config.json

@@ -1,6 +1,6 @@
 {
   "id": "events",
-  "version": "1.6.8-aio.3",
+  "version": "1.6.8-aio.4",
   "name": "Events",
   "repo": "https://git.atitlan.io/aiolabs/events",
   "short_description": "Sell and register event tickets",