docs(kit): pin core 1.19.0; teach the public demo's module members

The pin moves from 6890a74 (1.17.0) to 69998ec (1.19.0, website#224),
past 1.18.0 (website#223). Both are the public demo (DEMO_MODE.md §10
step 3). The chapters were read again for both versions:

- Chapter 2: a new section on a public demo site, covering demoLocks in
  module.json, ctx.demoMode and api.onDemoSeed (1.18.0). The call count
  becomes twenty.
- Chapter 5: a paragraph on an event action's demoRefuses (1.19.0), and
  a line in the action listing.

The one other core change in the window (website#221) is a wording fix
on core's Teams panel and nothing a module sees. The template declares
none of the new members, so template/module.json's coreApi becomes
^1.19.0 for the equality check only.

Checks run at the new pin:
- checkCoreApi, links, rename sites and chapter paths all pass, and so
  do the script tests (10 and 11).
- The template's imports, build, externals and swagger checks pass.
- Tests pass: server 82, client 20.
- The template was loaded as `examplegame` into a real core at this ref
  through core's own loader, with DEMO_MODE unset and with it true, and
  it registered both times.

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

ci/core-ref.json

@@ -1,10 +1,23 @@
 {
   "repo": "https://gitea.whitlocktech.com/RunicGateway/website.git",
   "branch": "main",
-  "ref": "6890a74c7c4ad5690509e8c163e477d7f7b399e7",
+  "ref": "69998ec54854d46681def92985a2b299ee3582a6",
   "why": [
     "The core this kit is written against, pinned to a commit rather than a branch.",
     "",
+    "2026-10-26: moved from 6890a74 (1.17.0) to 69998ec (1.19.0, website#224),",
+    "past 1.18.0 (website#223). Both are the public demo (DEMO_MODE.md), and the",
+    "chapters were read again for both versions:",
+    "- 1.18.0: demoLocks in module.json, ctx.demoMode and api.onDemoSeed",
+    "  (chapter 2 gains a section, and its call count becomes twenty);",
+    "- 1.19.0: an event action's demoRefuses (chapter 5, a paragraph and a line",
+    "  in the action listing).",
+    "The one other core change in the window (website#221) is a wording fix on",
+    "core's Teams panel and nothing a module sees. The template declares none of",
+    "the new members, so nothing it does changed meaning; module.json's coreApi",
+    "becomes ^1.19.0 for the equality check. The real core run was repeated at",
+    "this ref, with the template as the only module in the directory.",
+    "",
     "2026-10-23: moved from 0a37a44 (1.12.0) to 6890a74 (1.17.0, website#220,",
     "the cutover that brought Steam sign-in and the Rust last fixes to `main`),",
     "past 1.13.0 to 1.16.0, which reached `main` together on 2026-10-22. The",