docs(kit): pin core 1.12.0; chapter 5 teaches progress() and ctx.events.expired

The pin moves from 655fbf3f (1.10.0) to 0a37a44 (1.12.0, website#210),
past 1.11.0 (website#209), which it had skipped. Chapter 5 was read
again for both versions:

- 1.11.0: a thing the game ends on its own schedule is reported with
  ctx.events.expired and filed `expired`, not `orphaned`.
- 1.12.0: an action's optional progress(), the line on a public event
  page. It answers for one reader, cheaply, and costs a line rather
  than the page when it fails. "What to build, in order" gains it as
  step 7.

The template declares neither, so nothing it does changed meaning.
template/module.json's coreApi becomes ^1.12.0 for the equality check.

Checks run at the new pin:

- checkCoreApi, links, rename sites and chapter paths all pass.
- The template's import, swagger, build and externals checks pass.
- Tests pass: server 82, client 20, scripts 10 and 11.
- The template was loaded as `examplegame` into a real core of this
  code through core's own loader, and it registered.

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

template/module.json

@@ -2,7 +2,7 @@
   "id": "examplegame",
   "name": "Example Game",
   "version": "0.1.0",
-  "coreApi": "^1.10.0",
+  "coreApi": "^1.12.0",
   "server": "server/index.js",
   "client": { "entry": "client/dist/entry.js" },
   "schema": "server/db/schema.sql",