feat(events): an event action's progress() on a live run's public page (MODULE_API 1.12.0)

An event action may declare an optional `progress(envelope)`: how its
step stands while the run is live. Core accepts two shapes and
interprets neither:

- a count: { label, left, of }, rendered "Bandits: 3 of 8 left";
- a percentage: { label, percent }, rendered "The Juggernaut: 62%".

How core asks:

- `events/progress.js` asks each step of a live run whose action has
  one. It passes the step's own held ledger rows and the reader's
  account id, so the module applies its own visibility.
- Each call has a 2 s deadline. A throw, a late answer or any other
  shape is a line not shown, never an error on the page.
- One answer per run and reader is cached for 5 s.
- The public event's live occurrence carries the lines as `progress`.
  The route takes an optional session for the reader.
- The page renders them under the phase label and re-reads them every
  15 s while the event is live.

Core stays game-agnostic: no game's words are in it. Additive, so a
minor bump. Module-uo declares ^1.10.0, registers no action with
progress(), and its actions and pages are unchanged.

From RunicNPC stage 8 (D304, D305).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

server/engagement-triggers.json

@@ -1,6 +1,6 @@
 {
   "_comment": "Generated event-trigger inventory - the authoritative freeze of CORE's engagement contract (docs/website/ENGAGEMENT.md 4.3). Regenerate with `npm run engagement:manifest` in website/server. A renamed variable, a changed type or a widened ceiling breaks stored templates and rules, so the diff here is the review signal. A module ships its own copy in its bundle; this file never contains one.",
-  "moduleApiVersion": "1.11.0",
+  "moduleApiVersion": "1.12.0",
   "triggers": [
     {
       "id": "event.phase.changed",